浏览完整合集。
2×2 Matrix Calculator
Find the determinant, trace, rank, eigenvalues and inverse of any 2×2 matrix in one step, with an animated transformation.
2D Distance Calculator
Calculate the straight-line Euclidean distance between two points on a plane, plus midpoint, slope and angle.
3-Sides Triangle Area Calculator
Calculate a triangle's area from all three side lengths using Heron's formula, plus angles, altitudes, inradius and circumradius.
30-60-90 Triangle Calculator
Solve a 30-60-90 special right triangle from any one side. Instantly get the short leg, long leg, hypotenuse, area and perimeter.
45-45-90 Triangle Calculator
Solve a 45-45-90 isosceles right triangle from either side. Get the two equal legs, hypotenuse, area, and perimeter instantly.
a+bi Form Calculator
Add, subtract, multiply and divide complex numbers in a+bi form; also computes modulus and argument for each number.
AAA Triangle Calculator (All Three Angles)
Solve a triangle from all three angles (AAA). Optionally supply one side to scale the triangle and find all sides, area, perimeter, and radii.
AAS Triangle Calculator (Angle-Angle-Side)
Solve a triangle from two angles and a non-included side (AAS) — find all sides, angles, area, perimeter, inradius, and circumradius via law of sines.
Absolute Change Calculator
Calculate the absolute change (net difference) and percentage change between two values instantly.
Absolute Value Inequalities Calculator
Solve absolute value inequalities of the form |ax + b| < c, ≤, >, ≥ and display the solution set on a number line.
Acute Triangle Calculator
Check if a triangle is acute and calculate its area, all angles, perimeter, inradius and circumradius from the three side lengths.
Add & Subtract Polynomials Calculator
Add or subtract two polynomials up to degree 3 by entering their coefficients — shows the result and a step-by-step like-terms solution.
Adding and Subtracting Fractions Calculator
Add or subtract two fractions with different denominators — finds the LCD, converts, computes, and simplifies step by step.
Adding Fractions Calculator
Add two fractions with any denominators — automatically finds the LCD, converts both fractions, and simplifies the result step by step.
Addition Calculator
Add two or three numbers instantly and see the sum, the full arithmetic expression, and a number line showing every addend.
Adjoint Matrix Calculator
Compute the adjoint (adjugate) matrix and determinant for any 2×2 or 3×3 matrix, with step-by-step cofactor working shown.
振幅、周期与相移计算器
求正弦波 y = A sin(Bx + C) + D 的振幅、周期、相移和垂直移动。
AND Calculator
Calculate the bitwise AND of two integers and see the result in decimal, binary, and hexadecimal.
Antilog Calculator
Calculate the antilogarithm (inverse log) of any value in any base: find b^x, 10^x (antilog₁₀), and e^x (antiln).
弧长计算器
计算曲线 y = f(x) 在 x = a 到 x = b 之间的弧长。
Arccos Calculator
Calculate arccos(x) — the inverse cosine of a value — in both degrees and radians. Input must be in [−1, 1].
Arcsin Calculator
Calculate arcsin(x) — the inverse sine of any value between −1 and 1 — in both degrees and radians.
Arctan Calculator
Calculate arctan(x) — the inverse tangent of any real number — in degrees and radians, with the complementary arccot.
Arcus Tangent Calculator
Calculate the inverse tangent (arctan) of any real number — returns the angle in radians, degrees and gradians.
两曲线间面积计算器
计算区间 [a,b] 上两函数 f 和 g 之间围成的面积。
Area of a Circle Calculator
Calculate the area, circumference and diameter of a circle from its radius — using the formula Area = π × r².
Area of a Trapezoid Calculator
Calculate the area, perimeter and midline of a trapezoid from its two parallel sides and height using Area = ½ × (a + b) × h.
Area of Oblique Triangle Calculator
Calculate the area of an oblique (non-right) triangle from two sides and their included angle using ½ × a × b × sin(C).
Area of Obtuse Triangle Calculator
Calculate the area and all angles of an obtuse triangle from its three side lengths using Heron's formula.
曲线下面积计算器
使用精确数值积分计算 a 到 b 之间曲线下方的面积。
ASA Triangle Calculator
Solve a triangle from two angles and the included side (ASA). Calculates all sides, the third angle, area, perimeter and height.
Associative Property Calculator
Verify the associative property for addition or multiplication with any three numbers — shows both groupings step by step.
平均值计算器
求任意一组数字的平均值,以及总和、个数、最小值和最大值。
Average Percentage Calculator
Calculate the simple average (arithmetic mean) of up to five percentage values — useful for grades, survey results, growth rates and more.
平均变化率计算器
计算函数在两个 x 值 a 和 b 之间的平均变化率(割线斜率)。
函数平均值计算器
利用积分均值定理,求函数在区间 [a,b] 上的平均值。
Babylonian Numbers Calculator
Convert any decimal integer (1–215,999) to its Babylonian cuneiform numeral representation in base-60 with a step-by-step decomposition.
Base of a Triangle Calculator
Find the base of a triangle from its area and height, or from two sides and the included angle using the law of cosines.
Bessel Function Calculator
Compute Bessel functions of the first kind J₀(x), J₁(x) and J₂(x) using the power series, and plot all three curves from x = 0 to 15.
大整数计算器
以精确大整数精度对超大整数进行加、减、乘、除、取模或幂运算。
Bilinear Interpolation Calculator
Interpolate a value at any (x, y) point inside a 2D rectangular grid using the four corner values — step-by-step.
Binary Addition Calculator
Add two binary numbers and see the sum in binary, decimal, and hex with a step-by-step carry trace.
Binary Division Calculator
Divide two binary numbers to find the quotient and remainder. See results in binary and decimal with the verification N = Q × D + R.
Binary Fraction Calculator
Convert decimal fractions to binary or binary fractions to decimal. Shows repeated ×2 steps and place-value bit contributions.
Binary Multiplication Calculator
Multiply two binary numbers using the shift-and-add method. See partial products, the binary result, and the decimal equivalent.
Binary Operations Calculator
Perform AND, OR, XOR, NOT, NAND, NOR, XNOR on binary number inputs. See results in binary, decimal, and hex with bit-by-bit steps.
Binary Subtraction Calculator
Subtract two binary numbers using the two's complement method. See the result in binary, decimal, and hex with step-by-step working.
Binomial Coefficient Calculator
Calculate the binomial coefficient C(n, k) — the number of ways to choose k items from n — with Pascal's triangle row visualised.
位旋转计算器(循环移位)
在固定宽度内将整数向左或向右旋转 k 位。离开一端的位从另一端回绕。
位设置、清除与翻转计算器
使用位掩码操作在整数中的位置 k 处设置、清除、翻转或测试单个位。
位移位计算器(左移与右移)
将整数逻辑或算术地向左或向右移动 k 位。以十进制、二进制和十六进制显示移位结果。
Bitwise Calculator
Perform bitwise AND, OR, XOR, NAND, NOR, XNOR and NOT on two integers within a 4, 8, 16, 32 or 64-bit register, with binary and hex output.
按位运算计算器(AND、OR、XOR、NOT)
对两个整数计算按位 AND、OR、XOR、NOT(以及 NAND/NOR/XNOR)。以十进制、二进制和十六进制查看结果。
布尔真值表计算器
为两个布尔变量在所选运算符(AND、OR、XOR、NAND、IMPLIES、IFF)下构建真值表。
Box Method Calculator
Multiply two binomials (ax + b)(cx + d) using the box (grid) method with step-by-step workings.
Cartesian to Polar Coordinates Calculator
Convert a Cartesian point (x, y) to polar coordinates (r, θ) — get the radius and angle in degrees and radians instantly.
卡特兰数计算器
计算第 n 个卡特兰数,统计平衡括号、二叉树、路径和三角剖分的数量。
Catenary Curve Calculator
Calculate the arc length, catenary parameter, and shape of a hanging cable or chain from its span and midpoint sag.
Ceiling Function Calculator
Calculate the ceiling ⌈x⌉ of any number — the smallest integer ≥ x — plus floor, round and truncate for comparison.
Center of Ellipse Calculator
Find the center (h, k) of any ellipse from its general conic equation Ax² + Bxy + Cy² + Dx + Ey + F = 0, including tilted ellipses.
Center of Mass Calculator
Calculate the center of mass (x̄, ȳ) for a system of up to three point masses in 2D using x̄ = Σ(mᵢxᵢ)/Σmᵢ.
Central Angle Calculator
Calculate the central angle of a circle from radius and arc length. Get angle in degrees and radians, sector area, and chord length.
Centroid Calculator
Find the centroid (geometric centre) of 2, 3 or 4 points in 2D space — the arithmetic mean of all x and y coordinates.
Centroid of a Triangle Calculator
Find the centroid (intersection of medians) of a triangle from its three vertex coordinates, plus side lengths, area and median lengths.
Change of Base Calculator
Compute log_b(x) for any positive base b and argument x using the change-of-base formula: log_b(x) = ln(x)/ln(b).
Characteristic Polynomial Calculator
Find the characteristic polynomial and eigenvalues of a 2×2 matrix. Enter a, b, c, d and get det(A − λI) = 0 with all roots shown.
Chinese Remainder Theorem Calculator
Solve a system of three simultaneous congruences using the Chinese Remainder Theorem (CRT) with step-by-step working.
Cholesky Decomposition Calculator
Compute the Cholesky decomposition L of a 2×2 symmetric positive-definite matrix A so that L × Lᵀ = A.
Circle Center Calculator
Find the center (h, k) and radius of a circle passing through any three non-collinear points.
Circle Diameter Calculator
Calculate circle diameter from radius, area, or circumference — plus area, circumference, and radius from any single input.
Circle Equation Calculator
Write the equation of a circle in standard form (x−h)²+(y−k)²=r² and general form from its center and radius.
Circle Formula Calculator
Apply all circle formulas at once: area, circumference, arc length, sector area, chord length, and segment area from radius and angle.
Circle Length Calculator
Calculate the arc length of a circle from its radius and central angle in degrees or radians.
Circle Measurements Calculator
Calculate the area, circumference, diameter and sector values of a circle from its radius in any unit.
Circle Perimeter Calculator
Calculate the circumference, arc length, chord length and sector or segment perimeter of a circle.
圆扇形面积计算器
由半径和圆心角计算圆扇形面积,显示为整个圆的一个扇片。
Circle Theorems Calculator
Apply circle theorems to find inscribed angles, arc length, chord, sector area and cyclic quadrilateral angles from a central angle.
Circumcenter of a Triangle Calculator
Find the circumcenter coordinates and circumradius of a triangle — the centre and radius of the unique circle passing through all three vertices.
Circumference and Area of a Circle Calculator
Find the circumference and area of a circle from its radius, diameter, or area using C = 2πr and A = πr².
Circumference Calculator
Calculate the circumference of a circle from its radius or diameter using C = 2πr.
Circumference to Diameter Calculator
Convert circumference to diameter using d = C ÷ π. Also finds the radius and enclosed area.
Circumference to Radius Calculator
Find the radius of a circle from its circumference using r = C ÷ (2π).
Circumscribed Circle Calculator
Calculate the circumradius and circumcircle area of a regular polygon or any triangle.
Classifying Triangles Calculator
Enter three side lengths to classify a triangle by sides (equilateral, isosceles, scalene) and by angles (acute, right, obtuse), plus all angles and area.
Clock Angle Calculator
Find the angle between the hour and minute hands of a clock at any time. Instant clock-hand angle calculator with animated clock face.
Cofactor Expansion Calculator
Compute the determinant of a 3×3 matrix by Laplace cofactor expansion along row 1, with full step-by-step working.
Cofunction Calculator
Find all six cofunction pairs — sin/cos, tan/cot, sec/csc — for any angle in degrees or radians.
Coin Rotation Paradox Calculator
Calculate how many times a rolling coin rotates when circling a fixed coin — including the paradoxical extra rotation.
科拉兹猜想计算器
为任意起始数生成科拉兹(3n+1)序列,并计算到达 1 的步数。
Column Space Calculator
Find the column space (range) of a matrix: dimension, rank, nullity, and basis vectors — via row reduction for matrices up to 4×4.
组合数计算器(nCr)
计算组合数 nCr——从 n 个物品中选择 r 个且顺序无关的方式数。
有重复的组合计算器
统计多重集选择:从 n 种类型中可重复选择 r 个,即 C(n+r-1, r)。
Common Denominator Calculator
Find the least common denominator (LCD) of two fractions and convert both to equivalent fractions so they can be added or compared.
Common Factor Calculator
Find all common factors (divisors) of two numbers and the greatest common factor (GCF), with step-by-step Euclidean algorithm.
Common Multiple Calculator
Find the least common multiple (LCM) of two numbers and list the first N common multiples — with formula, GCF, and animated sequence.
Comparing Fractions Calculator
Compare two fractions and find which is greater, equal or smaller — with cross-multiplication steps, common denominators and decimal equivalents.
Compatible Numbers Calculator
Find compatible numbers (friendly round numbers) for quick mental arithmetic and see how close the estimate is to the exact answer.
Complementary Angles Calculator
Find the complement of any angle (90° − θ), plus its supplement, explementary angle and all six trig cofunction identities.
Complex Number Calculator
Add, subtract, multiply or divide two complex numbers and find their modulus, argument and Argand-diagram representation.
Complex Number to Polar Form Calculator
Convert a complex number a + bi to polar form r∠θ — find the magnitude and argument instantly.
Complex Number to Rectangular Form Calculator
Convert polar form r∠θ to rectangular form a + bi using r·cos(θ) and r·sin(θ).
Complex Number to Trigonometric Form Calculator
Convert a + bi to trigonometric form r(cos θ + i·sin θ) — find modulus and argument instantly.
Complex Root Calculator
Find all n complex roots of any complex number a + bi using De Moivre's theorem — roots plotted on the unit circle.
Condense Logarithms Calculator
Condense a sum or difference of two logarithms into a single log using the power, product and quotient rules, with step-by-step working.
Condition Number Calculator
Compute the spectral and Frobenius condition numbers of a 2×2 matrix from its singular values, with an interpretation of numerical stability.
Cone Surface Area Calculator
Calculate the lateral and total surface area of a cone from its base radius and height, including slant height and base area.
Cone Volume Calculator
Calculate the volume of a cone from its base radius and height: V = (1/3)·π·r²·h, plus slant height, base area and surface area.
Conic Sections Calculator
Explore properties of circles, ellipses, parabolas and hyperbolas — equations, eccentricity, foci, asymptotes and plotted curves.
Conjugate Calculator
Find the complex conjugate of z = a + bi: flip the sign of the imaginary part to get a − bi, with modulus, argument and modulus squared.
Consecutive Integers Calculator
Find the sum, mean, range and product of k consecutive integers starting at n. Visualise the sequence on a number line.
Convolution Calculator
Compute the discrete linear convolution of two finite sequences using the standard sum-of-products formula.
Coordinate Distance Calculator
Calculate the Euclidean and Manhattan distance between two 2D points, plus midpoint, slope and Pythagorean diagram.
Coordinate Grid Calculator
Enter two coordinate points and get slope, distance, midpoint, line equation, y-intercept and quadrant — with a live coordinate grid plot.
Corner Point Calculator
Find the corner point (vertex) where two constraint lines intersect using Cramer's rule — a key step in the linear programming corner-point method.
Cos Calculator
Calculate the cosine of any angle in degrees or radians — plus sine, tangent and cotangent, instantly.
cos(2θ) Calculator
Calculate cos(2θ) using all three double-angle identities, plus sin(2θ) and tan(2θ), for any angle in degrees or radians.
cos⁻¹ Calculator
Calculate cos⁻¹(x) — the inverse cosine — in degrees and radians for any cosine value from −1 to 1.
Cosecant Calculator
Calculate the cosecant (csc) of any angle in degrees or radians. Shows csc(θ) = 1/sin(θ), all six trig functions, and a step-by-step solution.
Cosh Calculator
Calculate cosh(x) — the hyperbolic cosine — plus sinh(x) and tanh(x), with a graph of the characteristic catenary curve.
Cosine Similarity Calculator
Compute cosine similarity between two vectors of any dimension: dot product over product of magnitudes. Returns similarity, angle, and cosine distance.
Cosine Triangle Calculator
Solve any triangle with the law of cosines. Enter two sides and the included angle (SAS) or all three sides (SSS) to find the missing side, all angles, area and perimeter.
Cot Calculator
Calculate the cotangent cot(θ) = cos(θ)/sin(θ) in degrees or radians — with sin, cos, tan and a graph of the cotangent function.
同终边角计算器
通过加减完整圆周,求任意给定角的正负同终边角。
Crescent Area Calculator
Calculate the area of a crescent (lune) formed by two overlapping circles of different radii and a given centre offset.
Cross Multiplication Calculator
Solve a proportion a/b = c/x for the unknown x using cross multiplication. See every step of the working.
Cross-Sectional Area Calculator
Calculate the cross-sectional area of circles, rectangles, triangles, ellipses, and hollow tubes — used in engineering and geometry.
Cube Root Calculator
Calculate the cube root of any number (positive, negative or zero) with step-by-step working and a y = ∛x graph.
Cube Surface Area Calculator
Calculate the total surface area of a cube from its side length. Instantly get face area, perimeter and space diagonal.
Cube V-A-D Calculator
Find the volume, surface area and diagonal of a cube from its side length. Covers space diagonal, face diagonal and total edge length.
Cube Volume Calculator
Calculate the volume of a cube from its side length using V = s³. Also shows surface area and space diagonal instantly.
Cubic Feet Cylinder Calculator
Calculate the volume of a cylinder in cubic feet from diameter and height. Also converts to cubic yards, cubic meters, liters and US gallons.
Cubic Inches in a Cylinder Calculator
Calculate the volume of a cylinder in cubic inches from diameter and height. Converts instantly to cubic feet, liters and US gallons.
Cubic Yards of a Cylinder Calculator
Calculate the volume of a cylinder in cubic yards from its diameter and depth in feet. Ideal for circular concrete pads, ponds and footings.
Cuboid Calculator
Calculate volume, total surface area, lateral surface area, space diagonal and face diagonals of a cuboid (rectangular box) from length, width and height.
Cuboid Surface Area Calculator
Calculate the total and lateral surface area of a rectangular cuboid (box) from its length, width and height using SA = 2(lw + lh + wh).
Cuboid Volume Calculator
Calculate the volume, surface area and space diagonal of a rectangular cuboid (box) from its length, width and height.
Cycloid Calculator
Calculate the arc length and area of a cycloid arch traced by a rolling circle of radius r. Shows parametric equations and animated curve plot.
Cyclomatic Complexity Calculator
Calculate McCabe's cyclomatic complexity (M = E − N + 2P) to measure code complexity and the minimum test paths needed.
Cylinder Circumference Calculator
Calculate a cylinder's base circumference (C = 2πr), diameter and lateral surface area from the radius and height.
Cylinder Diameter Calculator
Find a cylinder's diameter from its circumference (d = C ÷ π) or from its radius (d = 2r), with base area and radius shown.
Cylinder Volume Calculator
Calculate the volume, base area, lateral surface area and total surface area of a cylinder from its radius and height.
Calculate the volume of a cylinder in litres, cm³ and m³ from its radius and height. Supports cm, mm, m, inches and feet.
Cylinder Volume in Gallons Calculator
Convert a cylinder's volume to US liquid gallons from dimensions in inches or centimetres — tanks, pools, pipes and drums.
Cylindrical Coordinates Calculator
Convert between cylindrical coordinates (ρ, θ, z) and Cartesian (x, y, z) in both directions. Instant results with angle in degrees.
Decagon Area Calculator
Calculate the area, perimeter, circumradius, inradius and longest diagonal of a regular decagon (10-sided polygon) from its side length.
Decagon Calculator
Calculate the area, perimeter, circumradius, inradius, and diagonals of a regular decagon (10-sided polygon) from any known measurement.
Decimal Calculator
Convert fractions to decimals (including repeating decimal detection) and decimals to simplified fractions, with step-by-step working.
Decimal Degrees to DMS Converter
Convert decimal degrees to degrees-minutes-seconds (DMS) and back for GPS coordinates, mapping and surveying.
Decimal to Fraction Calculator
Convert any decimal to a simplified fraction and mixed number instantly, showing the step-by-step method.
Decimal to Percent Calculator
Convert any decimal number to a percentage instantly — multiply by 100 and see the result with a visual proportion bar.
定积分计算器
使用精确原函数计算常见函数从 a 到 b 的定积分。
角度与弧度转换器
在角度与弧度之间即时转换,并将结果以 π 的简洁倍数形式显示。
Descartes' Rule of Signs Calculator
Apply Descartes' rule of signs to count the possible numbers of positive and negative real roots of any polynomial.
Determinant Calculator
Calculate the determinant of a 2×2 or 3×3 matrix with full step-by-step cofactor expansion and a geometric visualisation.
Diagonal of a Rectangle Calculator
Find the diagonal of a rectangle from its length and width using the Pythagorean theorem, plus area and perimeter.
Diagonalize a 2×2 Matrix Calculator
Find the eigenvalues, eigenvectors, and diagonal decomposition A = PDP⁻¹ of a 2×2 real matrix, with step-by-step working.
Diameter of a Cone Calculator
Find the base diameter of a cone from its radius, plus slant height, volume, and surface areas in one step.
Diameter to Radius Calculator
Convert between diameter and radius of a circle and get circumference and area instantly — works in both directions.
Diamond Problem Calculator
Find the two numbers that multiply to the top and add to the bottom of the diamond puzzle — instantly solves any diamond problem.
数字和与数字根计算器
计算任意数各位数字之和,并通过反复求和得到其数字根。
Digital Root Calculator
Find the digital root of any whole number by repeatedly summing its digits until one digit remains.
Dimensions of a Rectangle Calculator
Enter length and width to instantly get the area, perimeter, diagonal and aspect ratio of any rectangle.
方向导数计算器
计算函数 f(x,y) 在某点沿指定方向向量的方向导数。
Distance Between Two Points Calculator
Calculate the straight-line distance between two Cartesian points (x₁,y₁) and (x₂,y₂) using the distance formula.
Distance Calculator
Calculate the Euclidean (straight-line) and Manhattan distances between two points in 2D using the distance formula d = √(Δx² + Δy²).
Distance from Point to Plane Calculator
Find the shortest (perpendicular) distance from a 3D point to a plane defined by ax + by + cz + d = 0.
Distributive Property Calculator
Apply the distributive property to expand a(b+c) or use FOIL to expand (a+b)(c+d) with a step-by-step solution.
Divide Complex Numbers Calculator
Divide two complex numbers (a+bi)÷(c+di) and get the real part, imaginary part and magnitude of the quotient.
Divide Fractions Calculator
Divide two fractions (a/b) ÷ (c/d) by multiplying by the reciprocal. Get the simplified fraction and decimal instantly.
Dividing Exponents Calculator
Divide exponents with the same base using the quotient rule: a^m ÷ a^n = a^(m−n). See the step-by-step solution instantly.
Dividing Radicals Calculator
Divide two square-root expressions (c₁√a) ÷ (c₂√b) using the quotient property. Get the rationalized form and step-by-step solution.
Divisibility Test Calculator
Test whether any integer is divisible by 2 through 11 instantly — with the shortcut rule shown for each divisor.
Divisor Calculator
Find every divisor of any integer up to 100 million. See the count, sum of divisors σ(N), and whether the number is perfect, abundant, or deficient.
Dodecagon Area Calculator
Find the area of a regular dodecagon from its side length, circumradius, or apothem. Includes perimeter and all key dimensions.
Dodecagon Calculator
Calculate area, perimeter, interior angle, circumradius, apothem and diagonal of a regular dodecagon from its side length.
Double Angle Calculator
Calculate sin(2θ), cos(2θ) and tan(2θ) for any angle using the double-angle formulas. Accepts degrees or radians.
Double Angle Formula Calculator
Apply the double-angle formulas step by step: evaluate sin(2θ), cos(2θ) and tan(2θ) with full working shown.
Double Angle Identities Calculator
Evaluate all double-angle identities — sin(2θ), all three forms of cos(2θ), tan(2θ) — plus derived half-angle values at any angle.
Doubling Time Calculator
Calculate how many periods it takes for a quantity to double at a given growth rate — exact formula and Rule of 72 compared.
e^x Calculator
Calculate e^x or b^x, see the Taylor series expansion term by term, the derivative, logarithm, and an interactive graph.
Egyptian Fraction Calculator
Decompose any positive fraction into a sum of distinct unit fractions (1/n) using the greedy algorithm, the method used in ancient Egyptian arithmetic.
Eigenvalue and Eigenvector Calculator
Calculate the eigenvalues and eigenvectors of a 2×2 matrix, solve the characteristic polynomial, and visualise how the matrix transforms space.
Elimination Method Calculator
Solve a system of two linear equations by elimination. Enter the six coefficients, get x and y with a step-by-step solution.
Ellipse Area Calculator
Calculate the area of an ellipse from its semi-major and semi-minor axes using the exact formula A = π × a × b.
Ellipse Perimeter Calculator
Calculate the perimeter (circumference) of an ellipse from its semi-axes using Ramanujan's highly accurate approximation formula.
Ellipse Standard Form Calculator
Enter center and semi-axes of an ellipse to get its standard equation, foci, eccentricity, area and a plot — all in one step.
Endpoint Calculator
Find the missing endpoint of a line segment given its midpoint and the other endpoint — instant coordinate geometry.
Engineering Notation Calculator
Convert any number to engineering notation — powers of 10 in multiples of 3, with matching SI prefix (k, M, G, m, μ, n, p…).
Equation of a Circle from Diameter Endpoints
Find the standard-form equation of a circle given the two endpoints of its diameter — calculates center, radius, area and circumference.
Equilateral Triangle Area Calculator
Calculate the area of an equilateral triangle from its side length or height — includes perimeter and derived dimensions.
Equilateral Triangle Calculator
Calculate the area, perimeter, height, inradius and circumradius of an equilateral triangle from its side length.
Equivalent Fractions Calculator
Find equivalent fractions by simplifying to lowest terms and scaling by any factor — shows a fraction bar and a table of common equivalents.
Equivalent Ratio Calculator
Find equivalent ratios by simplifying a:b to its lowest terms and scaling by any integer — shows a ratio bar and a table of common equivalents.
Error Function Calculator
Calculate the Gaussian error function erf(x), complementary error function erfc(x), and scaled erfc for any real x.
Euclidean Algorithm Calculator
Find the GCD of two integers using the Euclidean algorithm — see every division step, from start to remainder zero.
Euclidean Distance Calculator
Calculate the straight-line (Euclidean) distance between two points in 2D or 3D space using the Pythagorean theorem.
Euler's Formula for Polyhedra Calculator
Verify or complete Euler's polyhedron formula V − E + F = 2. Enter any two of vertices, edges and faces to find the third.
欧拉函数(phi)计算器
计算欧拉函数 phi(n):从 1 到 n 中与 n 互质的整数个数。
Exact Value of Trig Functions Calculator
Get the exact radical form (e.g. √3/2) and decimal value of sin, cos, tan, csc, sec and cot for all standard angles 0°–360°.
Expanded Form Calculator
Write any number in expanded form: break it into place-value addends (4523 = 4×1000 + 5×100 + 2×10 + 3) with powers of 10.
Expanding Logarithms Calculator
Expand logarithmic expressions using the product, quotient, and power rules. Shows the expanded symbolic form and computes the numeric result.
指数计算器
用这个指数计算器将任意底数升至任意次幂,支持负指数、分数指数和小数指数。
Exponential Form Calculator
Convert any number to scientific notation (exponential form) and find its mantissa, exponent, log₁₀, and natural logarithm.
Exponential Function Calculator
Evaluate f(x) = a × bˣ, determine growth or decay type, find the doubling time or half-life, and plot the exponential curve.
Exponential Growth Calculator
Calculate the final value, total growth and doubling time for discrete or continuous exponential growth.
Exponential Notation Calculator (Scientific Notation Converter)
Convert any number to scientific notation, engineering notation and E notation with a chosen number of significant figures.
Exterior Angles of a Triangle Calculator
Calculate all three exterior angles of a triangle from two interior angles and verify the exterior angle theorem.
Factor Calculator
Find the prime factorisation, all divisors, number of divisors and sum of divisors for any positive integer up to 1,000,000.
阶乘计算器
计算任意非负整数的阶乘 n!,即从 1 到 n 所有整数的乘积。
Factoring Trinomials Calculator
Factor a quadratic trinomial ax² + bx + c into a(x − r₁)(x − r₂) using the quadratic formula, with step-by-step working and a parabola graph.
因数计算器
列出整数的所有因数(除数),计算因数个数、总和,并配对每个因数与其互补因数。
Fermat's Little Theorem Calculator
Compute a^(p−1) mod p to verify Fermat's little theorem, test primality and find the modular inverse a⁻¹ (mod p).
斐波那契数列计算器
求第 n 个斐波那契数,列出前 n 项数列,并计算累积和。
Fifth Root Calculator
Calculate the fifth root of any real number instantly. Works for negative inputs, with a curve showing y = ⁵√x.
Floor Division Calculator
Calculate floor division ⌊a ÷ b⌋ and the true modulo remainder. Handles negative numbers correctly by rounding toward −∞, not toward zero.
Floor Function Calculator
Calculate the floor ⌊x⌋, ceiling ⌈x⌉, round, truncate and fractional part of any real number, with a number-line visualisation.
Foci of an Ellipse Calculator
Find the foci, eccentricity, area and perimeter of an ellipse from its semi-major axis a and semi-minor axis b.
FOIL Calculator
Expand (ax + b)(cx + d) using the FOIL method with full step-by-step working — First, Outside, Inside, Last — and get the simplified polynomial.
Fourth Root Calculator
Calculate the fourth root of any non-negative number — the value that, raised to the power 4, equals x.
分数计算器
对两个分数进行加、减、乘或除运算,并即时得到化简后的结果及其小数值。
Fraction to Decimal Calculator
Convert any fraction to its decimal and percentage equivalents, simplify the fraction, and show the mixed-number form.
Fraction to Percentage Calculator
Convert any fraction to a percentage instantly. Enter the numerator and denominator to get the exact percentage, decimal equivalent and a visual bar.
Fractional Exponent Calculator
Evaluate x^(p/q): raise any number to a fractional power and see the equivalent radical form plotted.
Fundamental Counting Principle Calculator
Multiply the number of choices for each independent event to find the total possible outcomes — up to 6 events.
Galileo's Paradox of Infinity Calculator
Explore Galileo's paradox: count natural numbers vs perfect squares in [1, N] and see why infinite sets defy 'more' and 'fewer'.
Gamma Function Calculator
Evaluate the Gamma function Γ(z) for any positive real number using the Lanczos approximation — accurate to ~15 significant digits.
Gauss–Jordan Elimination Calculator
Solve a 2×2 system of linear equations step by step using Gauss–Jordan elimination with full row-operation working.
最大公约数与最小公倍数计算器
使用欧几里得算法求一组整数的最大公约数 (GCD/HCF) 和最小公倍数 (LCM)。
GCD Calculator
Find the greatest common divisor of two integers using the Euclidean algorithm, with every step shown.
GCF and LCM Calculator
Find the Greatest Common Factor (GCF) and Least Common Multiple (LCM) of two numbers using the Euclidean algorithm, with step-by-step working.
GCF Calculator
Find the greatest common factor (GCF) of two or more integers — lists all common factors and simplifies fractions.
General Form Equation of a Circle Calculator
Convert a circle's centre (h, k) and radius r to its general form x² + y² + Dx + Ey + F = 0.
General to Standard Form Circle Calculator
Convert a circle from general form x² + y² + Dx + Ey + F = 0 to standard form (x−h)² + (y−k)² = r² by completing the square.
Geometric Mean Calculator
Calculate the geometric mean of any list of positive numbers — the n-th root of their product. Useful for growth rates, ratios and log-scale data.
Golden Rectangle Calculator
Calculate both sides, area, perimeter and diagonal of a golden rectangle from one side, using the golden ratio φ ≈ 1.6180.
梯度向量计算器
求二元函数在某点的梯度向量及其模长。
Gram-Schmidt Calculator
Apply the Gram-Schmidt process to two 2-D vectors and compute the orthonormal basis e₁, e₂ step by step.
完全图边数计算器
计算 n 个顶点完全图的边数:无向图为握手数 n(n-1)/2,有向图为 n(n-1)。
Graphing Inequalities on a Number Line Calculator
Solve and graph a linear inequality ax + b > c on a number line — shows boundary, interval notation, and open/closed endpoint.
Graphing Quadratic Inequalities Calculator
Solve and graph ax² + bx + c > 0 (or ≥, <, ≤) — shows roots, vertex, solution set, and parabola graph.
Great-Circle Distance Calculator
Calculate the shortest distance between two points on Earth using the haversine formula: result in km, miles and nautical miles, plus the initial bearing.
Greater Than Less Than Calculator
Compare any two numbers and find whether A > B, A < B or A = B, plus the difference, ratio and percentage change between them.
Greatest Common Denominator Calculator
Find the GCD of two denominators and the least common denominator (LCD) needed to add or subtract two fractions, with the simplified result.
Greatest Common Divisor Calculator
Find the greatest common divisor (GCD) of two integers using the Euclidean algorithm, with full step-by-step working and the LCM as a bonus result.
Greatest Common Factor Calculator
Find the Greatest Common Factor (GCF) of two or more integers and list all their common factors, with Euclidean algorithm steps.
Hadamard Product Calculator
Compute the Hadamard (element-wise) product of two 2×2 matrices — multiply matching entries and see the step-by-step working.
Half-Angle Calculator
Compute sin(θ/2), cos(θ/2) and tan(θ/2) from any angle in degrees or radians using the half-angle identities.
汉明距离计算器
求两个等长二进制(或十六进制)字符串的汉明距离:位不同的位置数。
Harmonic Mean Calculator
Calculate the harmonic mean of a list of non-zero numbers — the correct average for rates, speeds, and prices per unit.
Harmonic Number Calculator
Compute the nth harmonic number H(n) = 1 + 1/2 + 1/3 + … + 1/n, its asymptotic approximation, and the Euler–Mascheroni constant.
Height of a Cone Calculator
Find the perpendicular height of a cone from its radius and slant height (h = √(l²−r²)), or from its radius and volume (h = 3V/πr²).
Height of a Cylinder Calculator
Find the height of a cylinder from its radius and volume (h = V/πr²) or from its radius and lateral surface area (h = A/2πr).
Height of a Square Pyramid Calculator
Find the perpendicular height of a square pyramid from its base side and slant height (h = √(l²−(a/2)²)), or from its base side and volume.
Hemisphere Surface Area Calculator
Calculate the curved surface area (CSA = 2πr²) and total surface area (TSA = 3πr²) of a hemisphere from its radius.
Heptagon Area Calculator
Calculate the area of a regular heptagon from its side length, circumradius or apothem, with all derived dimensions.
Heptagon Calculator
Calculate the area, perimeter, apothem, circumradius, interior angles and diagonals of a regular heptagon from its side length.
十六进制与二进制算术计算器
对两个十六进制或二进制数进行加减运算,并同时以十六进制、二进制和十进制显示结果。
Hexagonal Pyramid Calculator
Calculate the volume, total surface area, lateral area and slant height of a regular hexagonal pyramid from base side and height.
Hexagonal Pyramid Surface Area Calculator
Find the total and lateral surface area of a regular hexagonal pyramid — enter base side and height, or base side and slant height.
Hilbert's Hotel Paradox
Explore Hilbert's Hotel paradox: see how infinitely many rooms can always accommodate more guests by shifting room assignments.
Hollow Cylinder Volume Calculator
Calculate the volume and surface area of a hollow cylinder (pipe or tube) from outer radius, inner radius and height.
Hyperbolic Functions Calculator
Calculate all six hyperbolic functions (sinh, cosh, tanh, coth, sech, csch) and their inverses for any x.
Hypotenuse Calculator
Calculate the hypotenuse or a missing leg of a right triangle using a² + b² = c². Also computes angles, area, and perimeter.
Imaginary Number (i) Calculator
Calculate powers of i (i^n = 1, i, −1, −i cycle), raise any complex number z = a+bi to the nth power, and find modulus, argument and conjugate.
Imaginary Number Calculator
Add, subtract, multiply or divide two complex numbers (a + bi) and find the result, modulus, argument and conjugate.
Improper Fraction to Mixed Number Calculator
Convert any improper fraction (numerator ≥ denominator) to a simplified mixed number in one step, with the full working shown.
Inequality to Interval Notation Calculator
Convert any linear inequality (x > a, x ≤ a, a < x ≤ b …) to interval notation instantly, with a number-line diagram.
Inscribed Angle Calculator
Calculate the inscribed angle from the central angle (arc) or vice versa. Applies the Inscribed Angle Theorem: inscribed angle = ½ × central angle.
Integer Calculator
Compute the GCD, LCM, quotient, remainder and basic arithmetic of any two integers instantly.
Intersection of Two Lines Calculator
Find the exact (x, y) intersection point of two lines given in slope-intercept form y = mx + b, with a live graph.
Interval Notation Calculator
Convert any inequality or set of real numbers to interval notation — with bracket type, set-builder form, and a number-line diagram.
Inverse Cosine Calculator
Find the angle whose cosine equals a given value. Returns arccos(x) in degrees, radians or gradians for any x in [−1, 1].
Find the angle from a cosine value or from adjacent and hypotenuse sides of a right triangle. Outputs degrees, radians, and gradians.
Inverse Sine Calculator
Find the angle whose sine equals a given value. Returns arcsin(x) in degrees, radians or gradians for any x in [−1, 1].
Inverse Tangent Calculator
Calculate arctan(x) or the quadrant-aware angle atan2(y, x) from coordinates — output in degrees and radians.
反三角函数计算器
计算某值的反正弦、反余弦或反正切,并以度和弧度两种形式给出所求角度。
Inverse Trigonometric Calculator
Calculate arcsin, arccos, arctan, arccsc, arcsec, or arccot of any valid input — angle in degrees and radians.
Involute Function Calculator
Calculate the gear involute function inv(α) = tan(α) − α and related gear parameters: base circle radius, module, addendum and dedendum.
Irregular Polygon Area Calculator
Find the area and perimeter of any irregular polygon from its vertex coordinates using the Shoelace formula.
Irregular Trapezoid Area Calculator
Calculate the area, perimeter, leg lengths and base angles of an irregular (general) trapezoid with two parallel sides and unequal legs.
Is Modulo Associative? Calculator
Test whether (a mod b) mod c equals a mod (b mod c) for any three integers — and learn why modulo is not generally associative.
Isosceles Trapezoid Area Calculator
Calculate the area, height, perimeter, diagonal, and angles of an isosceles trapezoid from its two bases and equal leg.
Isosceles Trapezoid Calculator
Calculate the area, height, perimeter, diagonal and base angles of an isosceles trapezoid from its two parallel sides and leg length.
Isosceles Triangle
Find the equal leg (a) of an isosceles triangle from the base and one other known value: height, area, or base angle.
Isosceles Triangle Angles Calculator
Calculate all three angles of an isosceles triangle from its sides, or find sides from the apex angle and base.
Isosceles Triangle Area Calculator
Calculate the area of an isosceles triangle from its equal side and base, or from the base and height directly.
Isosceles Triangle Calculator
Calculate the area, height, perimeter, angles, and medians of an isosceles triangle from its equal side and base.
Isosceles Triangle Height Calculator
Find the height (altitude) of an isosceles triangle from its equal side and base, from area and base, or from the equal side and apex angle.
Isosceles Triangle Side Calculator
Calculate the height, area, perimeter and angles of an isosceles triangle from its two equal legs and base.
Kite Area Calculator
Calculate the area and perimeter of a kite (quadrilateral) from its two diagonals. Formula: Area = (p × q) ÷ 2.
Lagrange Error Bound Calculator
Calculate the Lagrange remainder bound for a Taylor polynomial: |Rₙ(x)| ≤ M · |x−a|^(n+1) / (n+1)!
Lateral Area of a Cone Calculator
Calculate the lateral (curved) surface area of a cone from radius and height or slant height: A = π·r·l, plus total surface area and volume.
Lateral Area of a Trapezoidal Prism Calculator
Calculate the lateral surface area of a trapezoidal prism from the four sides of the trapezoid and the prism height.
Lateral Surface Area of a Cylinder Calculator
Calculate the lateral (curved) surface area of a cylinder from radius and height, with total surface area and volume.
Latus Rectum Calculator
Calculate the latus rectum and semi-latus rectum of a parabola, ellipse or hyperbola from its defining parameters.
余弦定理计算器
应用余弦定理,由三角形两边及夹角求第三边,或由三边求角。
正弦定理计算器
使用正弦定理,由已知边角对求三角形的未知边或角。
LCD Calculator
Find the Least Common Denominator (LCD) of two or three fractions instantly, with step-by-step multipliers and a visual breakdown.
LCM Calculator
Find the Least Common Multiple (LCM) of two or three integers using the GCD / Euclidean algorithm, with step-by-step working.
Least Common Denominator Calculator
Find the Least Common Denominator (LCD) of two or three fractions, convert them to equivalent fractions and compute their sum.
Least Common Factor Calculator
Find the least (smallest) factor greater than 1 that two integers share — the smallest prime factor of their GCF.
Least Common Multiple Calculator
Find the Least Common Multiple (LCM) of up to four integers using the GCD method, with full step-by-step working shown.
Least Squares Regression Calculator
Find the least-squares regression line (y = mx + b), correlation coefficient r, and R² for any set of x,y data points.
Length and Width of Rectangle Given Perimeter Calculator
Find the width of a rectangle when the perimeter and length are known. Also computes area, half-perimeter, and diagonal.
Length of a Line Segment Calculator
Calculate the distance between two coordinate points using the distance formula d = √((x₂−x₁)²+(y₂−y₁)²).
Length of a Rectangle Calculator
Find the length of a rectangle from its width and either its area (l = A ÷ w) or its perimeter (l = P/2 − w).
极限计算器
通过对两侧数值探测,估计函数在 x 趋近某值时的极限。
Line of Intersection of Two Planes Calculator
Find the parametric equation of the line where two planes intersect — direction vector via cross product and a point on the line.
Linear Feedback Shift Register (LFSR) Calculator
Generate the output bit sequence of a Fibonacci LFSR with a maximal-length polynomial — choose stages (2–8), initial state, and steps.
Linear Independence Calculator
Check whether three vectors in ℝ³ are linearly independent by computing the 3×3 determinant of the matrix they form.
Linear Interpolation Calculator
Find an unknown y that lies on the straight line between two known (x, y) data points — the standard lerp formula.
Log Base 2 Calculator
Calculate the base-2 logarithm of any positive number, with log₁₀ and natural log shown alongside a plotted curve.
对数计算器
计算任意正数以任意底的对数,外加自然对数 (ln) 和常用对数 (log₁₀)。
Logarithm Calculator
Calculate the logarithm of any positive number in base 10, natural (e), base 2, or a custom base instantly.
Long Addition Calculator
Add two whole numbers using the long addition method, with a full column-by-column breakdown showing every carry.
Long Division Calculator
Divide two whole numbers using the long division method, with a step-by-step breakdown showing each digit, subtraction and remainder.
Long Multiplication Calculator
Multiply two whole numbers using the long multiplication method, showing each partial product and the final addition step by step.
Long Subtraction Calculator
Subtract two whole numbers using the long subtraction method, with a full column-by-column breakdown showing every borrow.
Lowest Common Denominator Calculator
Find the lowest common denominator (LCD) of 2–4 fractions instantly, with step-by-step GCD/LCM working and a visual number line.
Lowest Term Calculator
Reduce any fraction to its lowest terms (simplest form) instantly using the Euclidean algorithm, with a full step-by-step GCD derivation.
LU Decomposition Calculator
Decompose a 3×3 matrix into lower (L) and upper (U) triangular factors using Doolittle elimination, with step-by-step working and determinant.
Luhn Algorithm Calculator
Validate any credit card, IMEI, or ID number using the Luhn algorithm checksum — with a step-by-step walkthrough.
Magic Square Calculator
Calculate the magic constant of an n×n magic square and display the actual grid for odd-order and doubly-even-order squares.
Manhattan Distance Calculator
Calculate the Manhattan (taxicab/city-block) distance between two 2D points: |x₂ − x₁| + |y₂ − y₁|.
Math Power Calculator
Calculate b raised to any power n — positive, negative, zero or fractional — with step-by-step working and a plotted power curve.
Matrix × Scalar Calculator (2×2)
Multiply a 2×2 matrix by a scalar — every element is scaled by k — with the resulting matrix, determinant, and a geometric view of the transformation.
Matrix Norm Calculator (2×2)
Calculate the Frobenius, 1-norm, ∞-norm and max-norm of a 2×2 matrix with step-by-step working and a comparison of all four norms.
极大值与极小值计算器
求函数在区间 [a,b] 上的绝对最大值和最小值。
Mayan Numeral Calculator
Convert any whole number to Mayan numerals — dots (1), bars (5), shell (0) — with a step-by-step base-20 decomposition and glyph display.
Mean Calculator
Calculate the arithmetic, geometric and harmonic mean of any list of numbers — enter values separated by commas.
中点法则计算器
用中点法则以 n 个矩形近似定积分。
Midsegment of a Triangle Calculator
Calculate all three midsegments of a triangle from its side lengths, plus the medial triangle area and perimeter.
Minutes to Decimal Degrees
Convert degrees, arc minutes and arc seconds (DMS) to decimal degrees — the format used in GPS, mapping, navigation and astronomy.
Miracle Calculator
Calculate how often a "miraculous" rare event is statistically expected using Littlewood's Law — enter the probability and daily event rate.
Mixed Number Calculator
Add, subtract, multiply or divide two mixed numbers — with full step-by-step working, simplification, and decimal result.
Mixed Number to Improper Fraction Calculator
Convert any mixed number to an improper fraction instantly — with step-by-step working and simplification using GCD.
Möbius Strip Calculator
Calculate the surface area and edge length of a Möbius strip given its radius and strip width, with a 2-D boundary curve diagram.
模幂计算器
使用快速平方取幂法和大整数,高效计算 (base^exponent) mod m。
模逆元计算器
求一个数的模乘逆元,即满足 a*x 与 1 同余于 mod m 的 x。
Modular Inverse Calculator
Find the modular multiplicative inverse of a modulo m using the extended Euclidean algorithm. Returns x where (a × x) mod m = 1.
取模计算器
求除法的余数和商,提供截断、向下取整和欧几里得三种取模变体以处理负数。
Modulo of Negative Numbers Calculator
See how modulo behaves with negative dividends or divisors across the three conventions: truncated (JS/C), floored (Python), and Euclidean.
Modulo Order of Operations Calculator
Explore how modulo (%) fits into PEMDAS/BODMAS precedence — same level as × and ÷ — with live worked examples and step-by-step evaluation.
Moore-Penrose Pseudoinverse Calculator (2×2)
Compute the Moore-Penrose pseudoinverse A† of any 2×2 matrix — handles full-rank, rank-1 and zero-matrix cases with verification.
Multiplication Calculator
Multiply any two numbers and see the product instantly. Works with decimals, negatives and large numbers.
Multiplicative Inverse Calculator
Find the multiplicative inverse (reciprocal) of any non-zero number. 1/x — the number that when multiplied by x gives 1.
Multiplicative Inverse Modulo Calculator
Find the multiplicative inverse of a number mod m — the x where a · x ≡ 1 (mod m), via the extended Euclidean algorithm.
Multiply Complex Numbers Calculator
Multiply two complex numbers (a + bi)(c + di) using FOIL — get the product, magnitude, and argument with an Argand-plane diagram.
Multiplying Binomials Calculator
Multiply two binomials (ax + b)(cx + d) using the FOIL method and get the expanded trinomial with step-by-step working.
Multiplying Exponents Calculator
Apply the product rule (xᵐ · xⁿ = x^(m+n)) or power rule ((xᵐ)ⁿ = x^(m·n)) to simplify and evaluate expressions with exponents.
Multiplying Fractions Calculator
Multiply two fractions (a/b × c/d) and instantly get the simplified result, decimal, and a step-by-step breakdown.
Multiplying Polynomials Calculator
Multiply any two polynomials by entering comma-separated coefficients — get the expanded product and a step-by-step distributive breakdown.
Multiplying Radicals Calculator
Multiply radical expressions c₁·ⁿ√a × c₂·ⁿ√b and simplify: extracts the largest perfect nth-power factor to give the fully simplified form.
Natural Log Calculator
Calculate ln(x), log base 10, log base 2, eˣ, and the derivative 1/x for any positive number — with an animated ln curve.
Negative Log Calculator
Calculate the negative logarithm −log_b(x) in base 10, e, or 2. Used for pH, pKa, pOH, decibels, and information-theoretic measures.
牛顿法计算器
从初始猜测值出发,用牛顿迭代法求函数的根。
NOR Calculator
Calculate the bitwise NOR of two integers — NOT(A OR B) — and see the result in decimal, binary, and hexadecimal.
Null Space Calculator
Find the null space (kernel) of a 2×2 matrix: compute its determinant, rank, nullity and a basis for the null space.
进制转换器
在二进制、八进制、十进制、十六进制及 2 到 36 进制之间转换数字。
进制转换计算器
在 2 到 36 进制之间转换数字(二进制、八进制、十进制、十六进制等),支持所有数字字符。
数字转英文文字转换器
将任意整数拼写为英文,例如 1234 变为 one thousand two hundred thirty-four。
数值导数计算器
用中心差分法求函数在某点处的导数,无需符号代数运算。
Oblique Triangle Calculator
Solve any oblique (non-right) triangle from SSS, SAS, AAS or SSA inputs — find all sides, angles, area, perimeter, inradius and circumradius.
Obtuse Triangle Calculator
Solve an obtuse triangle (one angle > 90°) — find all sides, angles, area, altitudes, inradius and circumradius from SSS or SAS inputs.
Octagon Calculator
Calculate area, perimeter, circumradius, inradius, and all three diagonal lengths of a regular octagon from any known measurement.
原码、反码与补码计算器
在选定位宽下,并排显示有符号整数的原码、反码和补码表示。
OR Calculator
Compute the bitwise OR of two integers in decimal, binary or hex, with a full bit-by-bit breakdown.
Order of Magnitude Calculator
Find the order of magnitude of any number: the integer exponent n so that |x| ≈ 10ⁿ. Also shows scientific notation and nearest powers of 10.
Orthocenter Calculator
Find the orthocenter of any triangle given its three vertices. Shows coordinates, type (acute/right/obtuse), area and a plotted diagram.
Parabola Calculator
Calculate the vertex, focus, directrix, axis of symmetry, x-intercepts and y-intercept of any parabola y = ax² + bx + c, with a live graph.
Parallelogram Area Calculator
Calculate the area of a parallelogram from its base and perpendicular height. Optionally enter the side to get the perimeter too.
Parallelogram Perimeter Calculator
Calculate the perimeter of a parallelogram from its base and side length using the formula P = 2(a + b).
奇偶校验位计算器(偶校验和奇校验)
计算二进制字的偶校验位和奇校验位,并统计其中的 1 位数,用于错误检测。
偏导数计算器
在某点处数值计算二元函数 f(x,y) 的偏导数。
Partial Products Calculator (Old Method)
Multiply two whole numbers using the old partial-products method — breaks each factor into place values and shows every multiplication step.
帕斯卡三角形行计算器
生成帕斯卡三角形的任意一行——k = 0 到 n 的二项式系数 C(n,k)。
Pentagon Calculator
Calculate the area, perimeter, circumradius, inradius, and diagonals of a regular pentagon from side length, circumradius, or apothem.
百分比变化计算器
计算旧值与新值之间的百分比增减,以及绝对差值。
Percent Time Calculator
Calculate what percentage of a time period has elapsed and how much time remains, using any consistent time unit.
Percent to Goal Calculator
Calculate what percentage of a goal you have achieved, how much remains, and what percent is left — for any numeric target.
百分比计算器
快速计算百分比:Y 的 X%、一个数是另一个数的百分之几,以及百分比变化。
Percentage Change Calculator
Calculate the percentage change between two values — finds the % increase or decrease from an original value to a new value.
Percentage Decrease Calculator
Calculate the value after a percentage decrease, or find what % one value fell from another — simple formula, instant result.
Percentage Difference Calculator
Calculate the percentage difference between two values — symmetric formula using the average as the reference, not one specific starting point.
Percentage Increase Calculator
Calculate the value after a percentage increase, or find what % one value rose from another — quick formula, instant result.
Percentage Point Calculator
Calculate the percentage point (pp) difference between two percentages and the relative % change — understand the key distinction between the two.
Perfect Cube Calculator
Check whether any integer is a perfect cube, find its exact integer cube root, and identify the nearest perfect cubes if it is not.
完全数计算器
通过将一个数与其真因数之和比较,检验它是完全数、盈数还是亏数。
Perfect Square Calculator
Check whether any non-negative integer is a perfect square, find its exact integer square root, and see the nearest perfect squares if it is not.
Perfect Square Trinomial Calculator
Expand a perfect square trinomial (a + b)² or (a − b)² into a² ± 2ab + b² with step-by-step working.
Perimeter Calculator
Calculate the perimeter of a circle, square, rectangle, triangle or regular polygon by entering the shape dimensions.
Perimeter of a Quadrilateral Calculator
Find the perimeter of any quadrilateral by entering all four side lengths — works for rectangles, parallelograms, rhombuses, and irregular shapes.
Perimeter of a Rectangle with Given Area Calculator
Find the perimeter of a rectangle when you know its area and one side — the calculator derives the other side and computes 2(l + w).
Perimeter of a Sector Calculator
Calculate the perimeter of a circular sector from the radius and central angle in degrees or radians — perimeter = 2r + arc length.
Perimeter of a Triangle Given Vertices Calculator
Find the perimeter and area of a triangle from its three vertex coordinates using the distance formula.
Perimeter of a Triangle with Fractions Calculator
Add fractional or mixed-number side lengths of a triangle to find the perimeter — supports entries like 3/4, 1 2/3, or 0.75.
Perimeter of Rectangle Calculator
Calculate the perimeter of a rectangle from its length and width, plus area, diagonal, and aspect ratio.
排列数计算器(nPr)
计算排列数 nPr = n!/(n-r)!——从 n 个元素中有序选取 r 个元素的排列数。
有重复的排列计算器
计算允许重复时的排列数:从 n 个符号中有序选取 r 个位置共 n^r 种方案。
Perpendicular Line Calculator
Find the equation of a line perpendicular to a given line through a specific point, plus the foot of the perpendicular and the shortest distance.
Pi Calculator
Approximate π using Nilakantha, Gregory–Leibniz or Machin series — see convergence, error and correct decimal places for any number of terms.
鸽巢原理计算器
应用鸽巢原理:求最满箱子中有保证的最小数量,以及迫使达到目标数量所需的物品数。
Place Value Calculator
Break any whole number into its place-value positions: ones, tens, hundreds, thousands and beyond.
Polar Decomposition Calculator
Decompose a 2×2 matrix into an orthogonal factor Q (rotation/reflection) and a symmetric positive semidefinite factor S (stretch). Exact closed-form result.
Polar Form Calculator
Convert a complex number a + bi to polar form r∠θ and Euler form r·e^(iθ). Find the modulus and argument in degrees and radians.
Polar to Cartesian Calculator
Convert polar coordinates (r, θ) to Cartesian (x, y). Enter radius and angle in degrees or radians to get the rectangular point instantly.
极坐标转直角坐标转换器
将极坐标 (r, theta) 转换为直角坐标 (x, y) 并绘制结果点。
Polish Notation Calculator
Evaluate expressions written in Polish (prefix) notation. Operators come before their operands — no parentheses needed. Supports +, -, *, /, ^.
Polygon Angle Calculator
Calculate the interior angle, exterior angle, and angle sum of any regular polygon. Enter the number of sides to get all angle properties instantly.
Polynomial Division Calculator
Divide one polynomial by another using long division. Enter coefficients in descending degree order and get quotient, remainder, and full working steps.
Polynomial Graphing Calculator
Graph polynomial functions up to degree 4, evaluate f(x), find real roots, and identify the vertex of a parabola.
位计数与位长度计算器
计算整数中置位(汉明重量)的数量和位长度,并检查其是否为 2 的幂。
Potato Paradox Calculator
Explore the Potato Paradox: calculate how much weight a batch loses when its water percentage drops slightly.
Power Function Calculator
Evaluate the power function y = a·xⁿ for any real coefficient, exponent and x value, with a plotted curve.
Power Modulo Calculator
Calculate (base^exponent) mod m — the remainder of a power divided by a modulus — using fast binary exponentiation.
Power of 10 Calculator
Calculate 10 raised to any power (10ⁿ) and see the result in standard and scientific notation.
Power of 2 Calculator
Calculate 2 raised to any power (2ⁿ) — instantly see memory sizes, bit depths and binary capacity values.
Power Reducing Calculator
Apply power-reducing identities to express sin²(θ), cos²(θ) and tan²(θ) in terms of cos(2θ) — enter any angle.
幂集与子集计算器
求 n 元集合幂集中子集的数量:共 2^n 个,另加真子集和非空子集的数量。
Powers of i Calculator
Calculate any integer power of the imaginary unit i. i cycles through 1, i, −1, −i with period 4 — enter any exponent to get the result instantly.
质因数分解计算器
将任意整数分解为质因数并显示指数形式,例如 360 = 2^3 x 3^2 x 5。
质数检验器
检验任意整数是否为质数,并使用直到平方根的快速试除法查看其质因数分解。
Prisoner's Dilemma Calculator
Enter the four payoff values of a prisoner's dilemma game to find the Nash equilibrium, Pareto-optimal outcome, and social cost of defection.
Pyramid Angle Calculator
Calculate all key angles of a right square pyramid: face inclination, lateral edge angle, apex angle, and the dihedral angle between adjacent faces.
Pyramid Volume Calculator
Calculate the volume, base area, lateral surface area, and total surface area of a square, rectangular, or equilateral-triangle-base pyramid.
Pythagoras Triangle Calculator
Solve any right triangle with the Pythagorean theorem. Enter any two sides to find the third, plus all angles, area, perimeter, and altitude to the hypotenuse.
Pythagorean Triples Calculator
Generate Pythagorean triples (a, b, c) with a² + b² = c² using Euclid's parametric formula for integers m > n ≥ 1.
QR Decomposition Calculator
Factor a 2×2 matrix A into an orthogonal matrix Q and upper-triangular matrix R using Gram-Schmidt orthogonalisation.
Quadratic Formula Calculator
Solve any quadratic equation ax² + bx + c = 0. Get both roots (real or complex), the discriminant, vertex, and a parabola plot.
Quadrilateral Area Calculator
Calculate the area of four common quadrilaterals: rectangle, parallelogram, trapezoid, and rhombus using exact formulas.
Quadrilateral Calculator
Calculate area, perimeter and diagonals for rectangles, parallelograms, isosceles trapezoids and rhombuses — select shape and enter dimensions.
Quarter Circle Area Calculator
Calculate the area of a quarter circle from its radius, or find the radius from a known area. Formula: A = πr²/4.
Quarter Circle Calculator
Calculate the area, arc length, perimeter and centroid of a quarter circle from its radius.
Quarter Circle Perimeter Calculator
Calculate the perimeter of a quarter circle: two radii plus the curved arc. Formula: P = 2r + πr/2.
Quaternion Calculator
Add, subtract or multiply two quaternions and compute the magnitude, conjugate and inverse. Shows step-by-step Hamilton product.
Queueing Theory Calculator (M/M/c)
Calculate M/M/c queue metrics: utilisation, average queue length, waiting time and service probability using the Erlang-C formula.
Quotient Calculator
Calculate the integer quotient and remainder of any division — shows truncated, floored and exact decimal results.
Radical Calculator
Calculate the nth root (square root, cube root, or any radical) of a number — with step-by-step result.
Radius of a Circle Calculator
Find the radius of a circle from its area, circumference, or diameter using simple inverse circle formulas.
Radius of a Cone Calculator
Find the base radius of a right circular cone from its volume, lateral surface area, or total surface area — given the height.
Radius of a Cylinder Calculator
Find the base radius of a right circular cylinder from its volume, lateral surface area, or total surface area — given the height.
Radius of a Sphere Calculator
Find the radius of a sphere from its volume or surface area, or compute volume, surface area and diameter from radius.
比率计算器
求解形如 a:b = c:d 的比例中的缺失值,并将任意比率化简为最简形式。
Ratio of Three Numbers Calculator
Simplify the ratio of three numbers to lowest terms and show each number as a percentage of the combined total A + B + C.
Ratio of Two Numbers Calculator
Find the simplified ratio of two numbers A : B, convert to a unit ratio, and see each number as a percentage of the combined total.
Rational Exponents Calculator
Evaluate x raised to a fractional exponent p/q, with step-by-step root-then-power working and a curve showing where your value falls.
Rational Zeros Calculator
Find all possible rational zeros of a polynomial using the Rational Root Theorem: ±(factors of constant term) ÷ (factors of leading coefficient).
Rationalize the Denominator Calculator
Rationalize the denominator of a/√b by multiplying by √b/√b, automatically simplifying perfect-square factors and reducing the resulting fraction.
Ratios of Directed Line Segments Calculator
Find the point that divides a line segment AB in a given ratio m:n — internally or externally — using the section formula.
Reciprocal Calculator
Find the reciprocal (multiplicative inverse) of any non-zero number: 1 ÷ x. Decimals, fractions and negatives all supported.
Rectangle Calculator
Calculate the area, perimeter, diagonal and aspect ratio of a rectangle from its length and width in any unit.
Rectangle Diagonal & Angle Calculator
Calculate the diagonal length and its angle in a rectangle from width and height. Uses the Pythagorean theorem and trigonometry.
Rectangle Length, Width & Area Calculator
Solve a rectangle from any two known values — length, width, area, or perimeter — and get all four measurements plus the diagonal.
Rectangle Scale Factor Calculator
Scale a rectangle by any factor: find new width, height, area, perimeter and diagonal. Area scales as k², linear dimensions scale as k.
Rectangular Prism Calculator
Calculate the volume, surface area, space diagonal and face diagonals of a rectangular prism (cuboid) from its length, width and height.
Rectangular Prism Volume Calculator
Calculate the volume, total surface area, lateral surface area, space diagonal and base perimeter of a rectangular prism from length, width and height.
Rectangular Pyramid Volume Calculator
Calculate the volume, base area, lateral and total surface areas, slant heights and apex edge of a rectangular pyramid from its base dimensions and height.
直角坐标转极坐标转换器
使用模和 atan2 角将直角坐标 (x, y) 转换为极坐标形式 (r, theta)。
参考角计算器
计算任意角度的参考角,并以度数或弧度显示其所在象限。
Regular Hexagon Calculator
Calculate area, perimeter, apothem, long and short diagonals of a regular hexagon from side length, apothem, perimeter or area.
Relative Change Calculator
Calculate the relative change (dimensionless ratio) and percent change between a reference value and a new value.
Relatively Prime Calculator
Check whether two integers are relatively prime (coprime) — GCD = 1 — using the Euclidean algorithm with every step shown.
Remainder Calculator
Find the quotient and remainder of integer division. Shows the full a = b × q + r breakdown step by step, including the modulo.
Reverse FOIL Calculator
Factor any quadratic ax² + bx + c into (px + q)(rx + s) using the AC / grouping method with step-by-step working.
Rhombus Area Calculator
Calculate the area and perimeter of a rhombus using diagonals, base and height, or side length and interior angle — three input methods.
黎曼和计算器
计算函数在区间上的左端点、右端点或中点黎曼和。
Right Circular Cone Calculator
Calculate the volume, total surface area, lateral surface area and slant height of a right circular cone from radius and height.
Right Cylinder Calculator
Calculate the volume, total and lateral surface area, base area and space diagonal of a right circular cylinder from radius and height.
Right Rectangular Pyramid Calculator
Calculate volume, total surface area, lateral surface area, slant heights and lateral edge of a right rectangular pyramid from base length, width and height.
Right Square Pyramid Calculator
Calculate volume, total surface area, lateral surface area, slant height and lateral edge of a right square pyramid from base side and height.
Right Trapezoid Area Calculator
Calculate the area of a right trapezoid from its two parallel bases and perpendicular height, with a step-by-step formula walkthrough.
Right Trapezoid Calculator
Calculate area, perimeter, slant side, diagonals and angles of a right trapezoid from its two parallel bases and perpendicular height.
直角三角形解算器
由任意两个已知量(直角边、斜边或锐角)求解直角三角形,包含面积和周长。
Rise Over Run Calculator
Calculate slope (rise ÷ run), angle in degrees and percent grade from rise/run values or two coordinate points.
求根计算器
求一个数的平方根、立方根或任意 n 次方根,包括负数的实奇次方根。
Root Mean Square Calculator
Calculate the root mean square (RMS) of any set of numbers. Works with positive and negative values; shows sum of squares and arithmetic mean.
Rotation Calculator
Rotate any 2D point (x, y) by any angle about the origin using the rotation matrix formula. Shows new coordinates, distance, and angles.
Round to the Nearest Cent Calculator
Round any dollar amount to the nearest cent ($0.01) — shows the rounded result, ceiling (always up), floor (always down) and the rounding difference.
Round to the Nearest Dollar Calculator
Round any dollar amount to the nearest whole dollar — shows the rounded result, ceiling (always up), floor (always down) and the rounding difference.
Round to the Nearest Hundred Calculator
Instantly round any number to the nearest 100. See the lower and upper hundreds and the rounding error.
Round to the Nearest Hundredth Calculator
Round any number to 2 decimal places (nearest 0.01). See the bounding hundredths and the exact rounding error.
Round to the Nearest Integer Calculator
Round any decimal to the nearest whole number. See floor, ceiling and rounding error instantly on a number line.
Round to the Nearest Penny Calculator
Round any monetary amount to the nearest cent or penny (2 decimal places). Essential for retail and financial calculations.
Round to the Nearest Ten Calculator
Round any number to the nearest multiple of 10. See the tens above and below and the rounding error instantly.
Round to the Nearest Tenth Calculator
Round any number to 1 decimal place (nearest 0.1). See the tenths above and below and the exact rounding error.
Round to the Nearest Thousand Calculator
Round any number to the nearest 1,000 instantly, with lower and upper bounding thousands and the rounding distance.
Round to the Nearest Thousandth Calculator
Round any number to three decimal places (nearest 0.001) with lower and upper bounding thousandths and the rounding error.
四舍五入计算器
将任意数四舍五入到选定的小数位数,或四舍五入到最接近的 10、100 或 1000,并给出向下取整和向上取整值。
Row Echelon Form Calculator
Convert any matrix to row echelon form (REF) step by step using Gaussian elimination with partial pivoting — up to 6 × 7.
RSA Calculator
Generate RSA public and private keys from two primes, then encrypt and decrypt an integer message — step by step.
SAS Triangle Calculator
Given two sides and the included angle (SAS), find the third side, all angles, area and perimeter using the Law of Cosines.
Scalene Triangle Area Calculator
Calculate the area, perimeter, heights and angles of a scalene triangle from its three side lengths using Heron's formula.
Scalene Triangle Calculator
Calculate the area, perimeter, all three angles, inradius and circumradius of any triangle from its three side lengths.
Scatter Plot Calculator
Plot (x, y) data pairs on a scatter chart, compute Pearson correlation r, R², and fit a least-squares regression line.
科学记数法计算器
在小数和科学记数法之间相互转换,显示尾数、指数和标准形式。
Sec Calculator
Calculate sec(θ) — the secant function — in degrees or radians, plus all six trig function values at the same angle.
二阶导数计算器
求函数在某点的二阶导数,并判断该处是向上凹还是向下凹。
Segment Addition Postulate Calculator
Apply the segment addition postulate AB + BC = AC to find any missing segment length instantly.
Segment Area Calculator
Calculate the area of a circular segment from the radius and central angle, plus arc length, chord, and sagitta.
Semicircle Area Calculator
Calculate the area, perimeter, arc length, and diameter of a semicircle given its radius.
Sequence Calculator
Calculate the nth term and sum of an arithmetic or geometric sequence. Enter the first term, common difference or ratio, and n.
Set Operations Calculator
Enter two sets of numbers to compute their union, intersection, difference and symmetric difference — with a visual number line.
集合运算计算器(并集与交集)
计算您输入的两个集合的并集、交集、差集和对称差,并显示元素数量。
Significant Figures Calculator
Count the significant figures in any number and round it to a specified number of sig figs, with a step-by-step explanation of the rules.
Similar Triangles Calculator
Find missing sides of similar triangles. Enter all three sides of the reference triangle and one corresponding side to get the scale factor and remaining sides.
Simplify Cube Root Calculator
Simplify ∛N by extracting the largest perfect-cube factor and expressing the result as k∛m in simplest radical form.
Simplify Fractions Calculator
Reduce any fraction to its lowest terms in one step using the GCD — shows the simplified form, decimal value, and a visual fraction bar.
Simplify Radicals Calculator
Simplify √N by extracting the largest perfect-square factor and writing the result as k√m in simplest radical form.
Simplify Ratio Calculator
Reduce a ratio A:B (or A:B:C) to its simplest whole-number form by dividing all parts by their GCD.
辛普森法则计算器
用辛普森法则(抛物弧线)近似定积分,实现高精度。
Sin Calculator
Calculate sin(θ), cos(θ), tan(θ) and cot(θ) for any angle in degrees or radians instantly.
正弦余弦正切计算器
一步求出任意度数或弧度角的正弦、余弦、正切及其倒数。
Sin Degrees Calculator
Find the sine of any angle entered in degrees. Also shows cosine, tangent and the equivalent angle in radians.
Sin Triangle Calculator
Solve a triangle using the Law of Sines: enter two angles and one side to find all remaining sides, angles, perimeter and area.
Sin, Cosine and Tangent Calculator
Calculate sin, cos, tan, cot, sec and csc for any angle in degrees or radians — all six trigonometric ratios at once.
sin(2θ) Calculator
Calculate sin(2θ) using the double-angle identity 2 sin θ cos θ, plus cos(2θ) and tan(2θ), for any angle in degrees or radians.
sin(θ) Calculator
Compute sin(θ) for any angle θ in degrees or radians, with the unit-circle coordinates, cos, tan and csc shown alongside.
Sin⁻¹ Calculator
Calculate sin⁻¹(x) — the angle whose sine equals x — in degrees and radians, for any x in [−1, 1].
Sine Function Calculator
Explore y = A·sin(Bx + C) + D: compute amplitude, period, frequency, phase shift and the function value at any x.
Singular Values Calculator
Compute the singular values σ₁ ≥ σ₂ of a 2×2 real matrix, plus condition number, nuclear norm and Frobenius norm.
Sinh Calculator
Calculate sinh(x), cosh(x), tanh(x) and coth(x) for any real x. Verifies the identity cosh²−sinh²=1 and plots the curve.
Slant Height Calculator
Calculate the slant height of a square pyramid from perpendicular height and base side — plus lateral area, total area and volume.
Slant Height of a Cone Calculator
Calculate the slant height of a cone from height and base radius — plus lateral area, total surface area, volume and apex half-angle.
Slope Percentage Calculator
Convert between slope percentage, angle (degrees), rise-over-run ratio and decimal slope in any direction. Useful for roads, ramps and roof pitches.
Slope-Intercept Form Calculator
Find the slope-intercept equation y = mx + b from two points, a point and slope, or m and b directly. Evaluate y at any x and plot the line.
Solve Similar Triangles Calculator
Find all sides of a similar triangle using the scale factor — enter the three sides of the original and one known side of the similar triangle.
Sphere Equation Calculator
Find the standard and general equation of a sphere in 3D from center coordinates and radius, plus volume and surface area.
Sphere Surface Area Calculator
Calculate the surface area of a sphere from its radius using 4πr². Also shows diameter, great-circle area and circumference.
Sphere Volume Calculator
Calculate the volume, surface area, diameter and circumference of a sphere from its radius or diameter with step-by-step working.
Spherical Coordinates Calculator
Convert between Cartesian (x, y, z) and spherical (r, θ, φ) coordinates in both directions, with radians and degrees.
Spiral Length Calculator
Calculate the exact arc length of an Archimedean spiral from inner radius, outer radius, and number of turns.
Square Area Calculator
Calculate the area, perimeter and diagonal of a square from its side length. Supports mm, cm, m, km, in, ft, yd and mi.
Square Diagonal Calculator
Calculate the diagonal of a square from its side length using d = s√2, plus area and perimeter.
Square Feet of a Rectangle Calculator
Calculate the area of a rectangle in square feet from length and width in any unit — feet, inches, yards or metres.
Square Inches of a Circle Calculator
Calculate the area of a circle in square inches from its diameter. Also converts to square feet and square centimetres.
Square Inscribed in a Circle Calculator
Find the side, area and perimeter of the largest square fitting inside a circle, given the radius — or vice versa.
Square of a Binomial Calculator
Expand (a + b)² using the binomial square identity a² + 2ab + b² — with step-by-step working.
Square Perimeter Calculator
Calculate the perimeter of a square from its side length using P = 4s, plus area and diagonal.
Square Pyramid Calculator
Calculate the volume, total surface area, lateral area, slant height, and lateral edge of a right square pyramid.
Square Pyramid Volume Calculator
Calculate the volume of a square pyramid from its base side and height using V = ⅓a²h, with step-by-step working.
Square Root Calculator
Calculate the square root of any non-negative number, plus reciprocal, cube root, and a visual y = √x curve.
SSA Triangle Calculator (Side-Side-Angle)
Solve a triangle from two sides and a non-included angle (SSA) — handles the ambiguous case where 0, 1, or 2 triangles exist.
SSS Triangle Calculator (Side-Side-Side)
Solve a triangle from all three side lengths (SSS) — find all angles, area, perimeter, inradius, circumradius and altitudes.
Standard Equation of a Circle Calculator
Write the standard (centre-radius) equation (x−h)²+(y−k)²=r² for any circle and find its area, circumference and axis intercepts.
Standard Form Calculator
Convert any number to standard form (scientific notation) a × 10ⁿ instantly, with the mantissa, exponent and step-by-step working.
Standard Form to Slope-Intercept Form Calculator
Convert a linear equation from standard form Ax + By = C to slope-intercept form y = mx + b, with step-by-step working and a line plot.
Standard Notation Calculator
Convert a number from scientific notation (a × 10ⁿ) to standard (decimal) notation with step-by-step decimal-place shifting.
Standard to General Form Circle Calculator
Convert a circle equation between standard form (x−h)²+(y−k)²=r² and general form x²+y²+Dx+Ey+F=0 in both directions.
Star Shape Calculator
Calculate the area, perimeter, side length, and tip angle of a regular n-pointed star polygon given its outer and inner radii.
第二类斯特林数计算器
计算第二类斯特林数 S(n,k):将 n 件物品划分为 k 个非空子集的方案数。
String Girdling Calculator
Solve the rope-around-the-Earth puzzle: how high does a rope rise when extra length is added to a loop around any sphere? Answer: Δr = ΔC ÷ 2π.
Subset Calculator
Count the subsets of a set with n elements: total 2ⁿ subsets, proper subsets, non-empty subsets and C(n,k) subsets of any size k.
Substitution Method Calculator
Solve a 2-variable linear system by substitution — enter the six coefficients and get x, y, a graph of the intersection, and every working step.
Subtracting Fractions Calculator
Subtract two fractions with different denominators — finds the LCD, converts both fractions, subtracts, and simplifies to lowest terms with every step shown.
Subtraction Calculator
Subtract any two numbers (integers or decimals) and see minuend, subtrahend, and difference on an animated number line.
Sum & Difference Identities Calculator
Calculate sin, cos, and tan of the sum (A+B) and difference (A−B) of two angles using the trigonometric sum and difference identities.
Sum of Linear Number Sequence Calculator
Calculate the sum of an arithmetic (linear) sequence given the first term, common difference and number of terms.
Sum of Series Calculator
Find the partial sum of an arithmetic or geometric series; shows the infinite-sum limit for convergent geometric series with |r| < 1.
SUMPRODUCT Calculator
Calculate SUMPRODUCT = Σ(aᵢ × bᵢ): multiply matching elements of two arrays then sum all the products — identical to a vector dot product.
Supplementary Angles Calculator
Find the supplementary angle (180° − θ) for any angle, plus the key trig identities sin(180°−θ) = sin θ and cos(180°−θ) = −cos θ.
Surface Area of a Cylinder Calculator
Calculate the total and lateral surface area of a cylinder from radius and height — TSA = 2πr(r + h).
Surface Area of a Rectangle Calculator
Calculate the area, perimeter and diagonal of a rectangle from its length and width using A = l × w.
Surface Area of a Rectangular Prism Calculator
Calculate the total surface area of a rectangular prism (cuboid) from length, width and height — TSA = 2(lw + lh + wh).
Surface Area of a Rectangular Pyramid Calculator
Calculate the total and lateral surface area of a rectangular pyramid from base length, base width and height.
Surface Area of a Square Pyramid Calculator
Calculate the total surface area of a square pyramid from its base side length and height — TSA = b² + 2bs.
Surface Area of a Triangular Prism Calculator
Calculate the total surface area and volume of a triangular prism from its three base sides and prism length.
旋转曲面面积计算器
计算曲线绕 x 轴从 a 到 b 旋转一周所生成的曲面面积。
Surface-Area-to-Volume Ratio Calculator
Calculate the SA:V ratio for a sphere, cube, cylinder or cuboid — essential in biology, chemistry and engineering.
SVD Calculator
Compute singular values, condition number, rank, Frobenius norm and spectral norm of a 2×2 matrix via SVD.
Tan Calculator
Calculate tan(θ) for any angle in degrees or radians — plus sin, cos, cot, sec and csc, with a plotted tangent curve.
Tan Inverse Calculator
Find the angle of a right triangle from its opposite and adjacent sides using the inverse tangent — with sin, cos, hypotenuse and a triangle diagram.
Tan⁻¹ Calculator
Calculate tan⁻¹(x) — the inverse tangent of any real number — in degrees or radians, with the matching right-triangle diagram.
Tangent Angle Calculator
Calculate the tangent of any angle in degrees or radians, with sin, cos, cot, sec, and a live plot of y = tan(x).
切线计算器
求函数在给定点 x = a 处切线的方程。
Tangent Ratio Calculator
Calculate the tangent ratio, missing side, or angle of a right triangle. Instantly find opposite, adjacent, hypotenuse, sin, and cos.
Tangent to a Circle Calculator
Find the tangent length from an external point to a circle, the tangent angle, power of a point, and triangle area using L = √(d² − r²).
Tanh Calculator
Calculate tanh(x) — the hyperbolic tangent — plus sinh(x), cosh(x) and the derivative sech²(x), with the characteristic S-curve plot.
泰勒多项式计算器
对函数在中心 c 处求 Taylor 多项式并与精确值对比。
Tensor Product Calculator
Compute the tensor (outer) product of two 2-D vectors: returns the 2×2 result matrix with all entries, Frobenius norm, trace, and determinant.
Terminating Decimals Calculator
Determine whether a fraction terminates or has a repeating decimal, and show the full decimal expansion with the repeating cycle in parentheses.
Tetrahedron Volume Calculator
Calculate the volume, surface area, height, inradius and circumradius of a regular tetrahedron from its edge length.
Theta (θ) Calculator
Calculate sin, cos, tan, cot, sec and csc for any angle θ in degrees or radians, with quadrant and reference angle.
Torus Surface Area Calculator
Calculate the surface area and volume of a torus (donut shape) from its major and minor radii using the Pappus theorem formulas.
Torus Volume & Surface Area Calculator
Calculate the volume and surface area of a torus (donut shape) from its major and minor radii using V = 2π²Rr².
Trapezoid Angle Calculator
Find all four interior angles of an isosceles trapezoid from the two parallel sides and the leg length.
Trapezoid Height Calculator
Calculate the perpendicular height of a trapezoid from its area and parallel sides, or from the equal leg length of an isosceles trapezoid.
Trapezoid Midsegment Calculator
Find the midsegment of a trapezoid from its two bases, find a missing base from the midsegment, or calculate the area using the midsegment and height.
Trapezoid Perimeter Calculator
Calculate the perimeter of a trapezoid from its four sides: two parallel bases and two non-parallel legs.
Trapezoid Side Calculator
Find a missing side of a trapezoid from the perimeter and three known sides, or from the area, height, and one base.
Trapezoidal Prism Volume Calculator
Calculate the volume and surface area of a trapezoidal prism from the two parallel bases, the trapezoid height, and the prism length.
梯形法则计算器
用梯形法则将积分区间分成 n 个子区间,估算曲线下的面积。
Triangle Angle Calculator
Find all three angles of a triangle from three sides (SSS) or two sides and the included angle (SAS) using the law of cosines.
Triangle Angles Calculator
Find the third interior angle of a triangle and all three exterior angles — with triangle classification (acute, right, obtuse, scalene, isosceles, equilateral).
Triangle Area Calculator
Calculate a triangle's area from base and height, two sides and an angle (SAS), or all three sides with Heron's formula.
Triangle Area from Coordinates Calculator
Find the area of a triangle from its three vertex coordinates (x₁,y₁), (x₂,y₂), (x₃,y₃) using the shoelace formula.
Triangle Area in Square Feet Calculator
Calculate the area of a triangle in square feet from its base and height in any unit — feet, inches, metres, or more.
Triangle Area SAS Calculator
Find the area of a triangle from two sides and the included angle (SAS) using A = ½ab·sin(C). Also derives the third side and all angles.
Triangle Calculator from Three Sides (SSS)
Solve a triangle from its three sides (SSS): find all angles via the law of cosines and the area, perimeter, inradius, and circumradius via Heron's formula.
Triangle Congruence Calculator
Check if two triangles are congruent or similar. Enter three sides for each triangle and see which congruence criteria (SSS, SAS, ASA, AAS, HL) apply.
Triangle Degree Calculator
Find the missing interior angle of a triangle in degrees. Enter two known angles; the third is computed as 180° minus their sum.
Triangle Height Calculator
Find all three altitudes (heights) of a triangle from its three side lengths using the area from Heron's formula.
Triangle Inequality Calculator
Check whether three side lengths satisfy the triangle inequality and can form a valid triangle. Shows all three conditions.
Triangle Perimeter Calculator
Calculate the perimeter, area, all three angles, inradius, and circumradius of any triangle from its three side lengths.
Triangle Proportionality Theorem Calculator
Apply the Triangle Proportionality Theorem: if a line is parallel to one side of a triangle, find the missing segment using AD/DB = AE/EC.
Triangle Ratio Calculator
Find the actual side lengths of a triangle whose sides are in a given ratio r₁:r₂:r₃, using the known perimeter.
Triangle Scale Factor Calculator
Find the scale factor between two triangles, verify similarity, and calculate scaled sides, area ratio and perimeter ratio.
Triangle Side Calculator
Find the missing side of a triangle (SAS) or all angles from three sides (SSS) using the Law of Cosines.
Triangle Side Length Calculator
Find the missing side of any triangle using the Law of Cosines (SAS) or the Law of Sines (AAS), plus all angles and area.
Triangle Side–Angle Calculator
Find all sides and angles of a triangle from two angles and one side (AAS or ASA) using the Law of Sines.
Triangle Similarity Calculator
Determine whether two triangles are similar using the SSS side-ratio test or the AA angle-equality test. Shows scale factor and area ratio.
Triangle Slope Calculator
Enter the three vertices of a triangle in the coordinate plane to find the slope, length and angle of each side, plus area and perimeter.
Triangle Sum Theorem Calculator
Use the triangle angle-sum theorem (A + B + C = 180°) to find any missing angle. Enter two angles and get the third instantly.
Triangle Vertices Calculator
Enter three vertex coordinates to instantly find a triangle's area, side lengths, angles, perimeter, centroid and type.
三角数计算器
计算第 n 个三角数(1+2+...+n)并查看三角数序列。
Triangular Prism Calculator
Calculate volume, total surface area, lateral area and hypotenuse of a right triangular prism from the two legs and prism length.
Triangular Pyramid Volume Calculator
Calculate the volume of a triangular pyramid (tetrahedron) from its base side, base altitude and perpendicular pyramid height.
Triangulation Calculator
Given a known baseline and two angles to a target, compute the distances from each observation point and the target's coordinates.
Trig Calculator
Calculate all six trigonometric functions — sin, cos, tan, csc, sec, cot — for any angle in degrees or radians.
Trig Degree Calculator
Convert any angle from degrees to radians and compute all six trig functions (sin, cos, tan, csc, sec, cot) with quadrant and reference angle.
Trig Identities Calculator
Verify the Pythagorean, quotient, reciprocal, double-angle and half-angle trigonometric identities numerically at any angle.
三角恒等式验证器
在给定角度处对所选三角恒等式的两侧分别求值,数值验证其成立。
Trig Triangle Calculator
Solve a general triangle from three sides (SSS) or two sides and the included angle (SAS) using the law of cosines — find all angles, sides, area and perimeter.
Trigonometric Functions Calculator
Plot any of the six trig functions with custom amplitude, frequency and phase shift. See period, frequency and key angle values on an interactive graph.
Trigonometry Calculator
Solve any right triangle from one angle and one side. Instantly find all three sides, the complementary angle, sin, cos, and tan.
Truncated Cone Calculator
Calculate the volume, lateral surface area and total surface area of a truncated cone (frustum) from the two base radii and height.
Truncated Cone Volume Calculator
Calculate the volume of a truncated cone (frustum) from two base radii and height. Formula: V = (π/3) h (r₁² + r₁r₂ + r₂²).
二补码计算器
在 8、16、32 或 64 位下将有符号十进制数转换为二补码二进制数及反向转换,并显示可表示范围。
Ugly Duckling Theorem Calculator
Explore Watanabe's Ugly Duckling Theorem: without feature weighting, any two objects share exactly 50% of all Boolean predicates — making all pairs equally similar.
Union and Intersection Calculator
Calculate the union, intersection, set difference and symmetric difference of two sets of numbers, with element counts and a Venn-diagram breakdown.
单位圆计算器
获取任意角度在单位圆上的精确 (cos, sin) 坐标,并在圆上绘制该点。
Unit Rate Calculator
Calculate the unit rate — value per single unit — for any price, speed, or ratio in one step.
Uses of Modulo Calculator
Explore the real-world uses of modulo: clock arithmetic, day-of-week cycling, even/odd testing, last-digit extraction, and circular array indexing — all from a single a mod n.
Vector Addition Calculator
Add up to three 2D vectors by components and find the resultant vector magnitude, direction angle, and a visual arrow diagram.
Vector Calculator
Calculate 2D vector magnitude, dot product, 2D cross product, angle between vectors and resultant sum — with an animated vector diagram.
Vector Direction Calculator
Find the direction angle, compass bearing, reference angle, quadrant, and unit vector for any 2D vector given components or magnitude and angle.
Vertex Form Calculator
Convert y = ax² + bx + c to vertex form y = a(x − h)² + k, find the vertex, axis of symmetry, roots and plot the parabola.
Volume of a Hemisphere Calculator
Calculate the volume, curved surface area, flat base area, and total surface area of a hemisphere from its radius.
Volume of a Hexagonal Pyramid Calculator
Calculate the volume, base area, lateral surface area, and total surface area of a regular hexagonal pyramid from its base side length and height.
Volume of a Parallelepiped Calculator
Calculate the volume and surface area of a parallelepiped from three edge lengths and the three pairwise angles using the scalar triple product.
Volume of a Triangular Prism Calculator
Calculate the volume, lateral surface area, and total surface area of a triangular prism from the three sides of its triangular base and its length.
旋转体体积计算器
求曲线绕 x 轴旋转所形成的旋转体体积(圆盘法)。
Width of a Rectangle Calculator
Find the width of a rectangle from its area and length, perimeter and length, or diagonal and length — plus all derived dimensions.
XOR Calculator
Calculate A XOR B for any two integers up to 32 bits. Shows the result in decimal, binary and hex with a step-by-step bit breakdown.
Y-Intercept Calculator
Find the y-intercept (b) of a line given its slope and any point on it. Plots the full line with x- and y-intercepts marked.
2×2 矩阵特征值计算器
通过特征方程求 2×2 矩阵的特征值。输入四个元素,得到实数或复数根。
绝对值方程求解器
求解 |ax+b|=c 中的 x,并绘制 y=|ax+b| 与 y=c 的图像以查看交点。
向量夹角计算器
使用点积公式求两向量之间的夹角。输入分量即可获得角度(度数和弧度)。
等差数列计算器
根据首项和公差求等差数列的第 n 项及其前 n 项之和。
二项式展开计算器
用二项式定理展开 (a+b)^n 并列出每一项的系数。
余子式与伴随矩阵计算器
求 2×2 或 3×3 矩阵的余子式矩阵和伴随矩阵(adjoint)。输入数字行即可同时得到两个矩阵。
配方计算器
将 ax^2+bx+c 改写为顶点式 a(x-h)^2+k 并读出顶点坐标。
克莱默法则计算器
用克莱默法则和行列式求解 2×2 或 3×3 线性方程组。输入系数和常数即可。
叉积计算器
计算两个三维向量的叉积。分别输入三个分量,得到垂直向量及其模。
三次方程求解器
求解 ax^3+bx^2+cx+d=0 的所有实数根和复数根,并绘制三次曲线图像。
正比例与反比例计算器
求变化常数 k 并利用正比例或反比例关系预测新值。
判别式计算器
求二次方程的判别式 b^2-4ac,立即查看其实根个数。
距离公式计算器
使用从勾股定理推导出的距离公式,计算两点 (x₁, y₁) 和 (x₂, y₂) 之间的直线距离。
点积计算器
计算两个等长向量的点(标量)积。用空格或逗号分隔输入各分量。
二次式因式分解计算器
利用根将 ax^2+bx+c 因式分解为 a(x-r1)(x-r2),支持实数或复数输出。
函数复合计算器
复合两个线性函数 f 和 g,并在某点求 (f∘g)(x) 的值。
等比数列计算器
根据公比计算等比数列的第 n 项、有限和与无穷和。
指数定律计算器
应用指数定律处理同底数幂:进行乘法、除法或乘方运算并化简。
直线方程计算器
根据两点求直线方程——斜截式 (y = mx + b)、点斜式和标准式,以及斜率和截距,并附带图像。
向量线性组合计算器
计算多个向量的线性组合 c1*v1 + c2*v2 + ...。将向量按行输入并附上对应的标量系数。
一元一次方程求解器
即时求解任何形如 ax + b = 0 的一元一次方程的 x。免费的一元一次方程计算器,提供分步解答并处理特殊情况。
一元线性不等式求解器
求解一元线性不等式 ax+b (</<=/>/>=) c,并在数轴上显示解集区域。
矩阵加法计算器
按元素对两个相同大小的矩阵求和。将每个矩阵以空格分隔的数字行形式输入,即刻得到结果矩阵。
矩阵行列式计算器
计算按数字行输入的 2×2 或 3×3 矩阵的行列式;自动检测矩阵大小。
矩阵求逆计算器
使用行列式和伴随矩阵求 2×2 或 3×3 矩阵的逆矩阵。输入数字行;矩阵必须非奇异。
矩阵乘法计算器
使用行列点积规则将两个矩阵相乘。将两个矩阵以数字行形式输入;大小必须兼容。
矩阵幂计算器
将方阵提升到整数幂次。将矩阵以数字行形式输入并指定指数,以计算 A 的 n 次幂。
矩阵秩计算器
使用高斯消元法求任意矩阵的秩。输入数字行以计算独立行数(非零主元数)。
矩阵减法计算器
按元素对一个矩阵减去另一个矩阵。将两个矩阵以数字行形式输入,查看差矩阵及每个步骤。
矩阵迹计算器
计算方阵的迹:主对角线元素之和。将矩阵以数字行形式输入。
矩阵转置计算器
通过翻转行和列求任意矩阵的转置。输入以空格分隔的数字行,即刻得到 A 的转置矩阵。
中点计算器
求坐标平面上两点 (x₁, y₁) 和 (x₂, y₂) 之间的中点。免费的中点公式计算器,显示 x 和 y 两个坐标。
三点求抛物线计算器
求经过三个点的抛物线的二次方程 y = ax² + bx + c,以及它的顶点、对称轴和判别式,并附带图像。
平行与垂直直线计算器
求经过某一点、与给定斜率平行和垂直的直线方程,以斜截式表示,并附带图像。
部分分式分解计算器
将 (px+q)/((x-r1)(x-r2)) 分解为 A/(x-r1)+B/(x-r2),适用于不同的线性因子。
百分比误差计算器
计算测量值与实际(真实)值之间的百分比误差。免费的百分比误差计算器,适用于科学实验、化学和物理。
点斜式计算器
根据一个点和一个斜率,用点斜式 y − y₁ = m(x − x₁) 写出直线方程,然后转换为斜截式和标准式,并附带图像。
多项式求值计算器
用 Horner 法在给定 x 处求解任意多项式 P(x) 的值,并绘制该点附近的曲线。
比例计算器
使用交叉相乘求解比例 a/b = c/x 中的未知数 x。免费的比例和比率求解器,适用于等值分数。
勾股定理计算器
用勾股定理求解直角三角形。从两条直角边求斜边,或从斜边和一条直角边求缺失的直角边。
一元二次方程求解器
用求根公式求解 ax² + bx + c = 0——包括实根和复根,以及判别式。
有理根定理计算器
从多项式的常数项和首项系数列出所有可能的有理根。
RREF 计算器(行最简阶梯形)
使用 Gauss-Jordan 消元法将任意矩阵化简为行最简阶梯形。输入数字行以查看 RREF。
矩阵标量乘法计算器
将矩阵乘以一个标量。按行输入矩阵和标量值,即可立即缩放每个元素。
标量三重积计算器
计算三个三维向量的标量三重积及其构成的平行六面体的体积。
斜率计算器
求两点之间直线的斜率,以及倾斜角和 y 轴截距。免费的斜率与上升量除以水平量计算器,并给出直线方程。
综合除法计算器
使用综合除法将多项式除以 (x-c),得到商式和余数。
二元一次方程组求解器 (2x2)
使用克莱姆法则求解 2x2 二元一次方程组。输入系数即可即时求出 x 和 y,并给出行列式和特殊情况检测。
单位向量计算器
将向量归一化为长度 1。输入分量,得到指向同一方向的单位向量及其模。
向量模计算器
求任意维度向量的模(长度/范数)。输入以空格或逗号分隔的分量,得到 |v|。
向量投影计算器
将一个向量投影到另一个向量上。输入向量 a 和 b,得到投影向量及 a 在 b 上的标量投影。
Acreage Calculator
Calculate the acreage of a rectangular, triangular or circular plot from its dimensions, with results in acres, sq ft, sq m and hectares.
Acres to Hectares Converter
Convert acres to hectares (and to square meters, square feet, square miles) instantly using the exact international conversion factor.
Acres to Square Feet Converter
Convert acres to square feet (and square yards, square inches, square meters) instantly. 1 acre = 43,560 sq ft exactly.
角度转换器
在度、弧度、百分度、角分、角秒和圈之间转换角度——即时且精确。
Angstrom to nm Converter
Convert angstroms (Å) to nanometres, picometres, micrometres and metres — 1 Å = 0.1 nm exactly.
面积转换器
在平方米、平方英尺、英亩、公顷、平方英里、平方千米等单位之间转换面积——即时且准确。
Ares to Cents Converter
Convert ares to cents (South Indian land unit) and to square metres, square feet, acres, and hectares. 1 are ≈ 2.4711 cents.
Ares to Hectares Calculator
Convert ares to hectares instantly. 1 are = 0.01 ha (exact). Also shows square meters, square feet and acres.
Astronomical Unit Calculator
Convert between astronomical units (AU) and kilometres, miles, metres, light-years, parsecs and light-minutes.
ATM Conversion Calculator
Convert atmospheres (atm) to pascal, kPa, bar, psi, mmHg, Torr, inHg and millibar — or convert any pressure unit to atm.
ATM to Pascals Conversion Calculator
Convert standard atmospheres (atm) to pascals, kilopascals, bar, PSI, and mmHg instantly — exact BIPM definition.
Bar to ATM Conversion Calculator
Convert bar to standard atmospheres (atm) — plus kPa, Pa, psi, mmHg and mbar. 1 bar = 0.986923 atm.
Bar to PSI Conversion Calculator
Convert bar to psi (pounds per square inch) — plus atm, kPa, mmHg and mbar. 1 bar = 14.5038 psi.
Bar to PSIG Conversion Calculator
Convert bar (absolute) to psig (gauge pressure in psi). 1 bar ≈ −0.192 psig because 1 bar < 1 atm.
Barometric Pressure Conversion Calculator
Convert barometric pressure between hPa, mbar, inHg, mmHg, Pa, kPa, atm and psi — with sea-level weather context.
Base64 编码大小计算器
估算数据经 Base64 编码后的大小,包含约 33% 的开销以及可选的换行/数据 URI 填充。
BCD(二进制编码十进制)转换器
将十进制数转换为紧缩二进制编码十进制(BCD)并反向转换,每个数字编码为独立的 4 位半字节。
Billion to Trillion Converter
Convert any number of billions to trillions, millions and quadrillions instantly — with the scale relationship shown step by step.
Binary Calculator
Convert any non-negative integer between binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16) instantly.
Binary to Hexadecimal Converter
Convert any binary number to hexadecimal instantly — with the nibble grouping that makes the 1-to-4 mapping visible.
Binary to Octal Converter
Convert a binary number to octal instantly — groups bits into triplets showing the 3-to-1 relationship.
Byte Converter
Convert digital data sizes between bits, bytes, KB, MB, GB, TB and binary KiB, MiB, GiB, TiB — with the decimal vs binary difference explained.
Capacitance Conversion Calculator
Convert capacitance between farads, millifarads, microfarads, nanofarads, picofarads and femtofarads instantly.
CC to Grams Converter
Convert cubic centimetres (cc) to grams using density. Choose a preset substance or enter a custom density.
CC to Liter Converter
Convert cubic centimetres (cc) to litres and back, plus mL, US gallons and fluid ounces — all exact SI definitions.
CC to mL Converter
Convert cc (cubic centimetres) to mL — they are identical — plus litres, fluid ounces, teaspoons, tablespoons and cups.
CC to Oz Converter
Convert cc (cubic centimetres / mL) to US or UK fluid ounces and back — plus litres, cups, pints, quarts and gallons.
CCF to Gallons Conversion Calculator
Convert CCF (hundred cubic feet) to US gallons, litres and cubic metres — used for water and natural gas billing.
CCF to Therms Calculator
Convert CCF (hundred cubic feet) of natural gas to therms and MMBtu using your gas's BTU content. For gas billing and energy use.
Celsius Converter
Convert Celsius to Fahrenheit, Kelvin and Rankine instantly with exact formulas and a visual temperature scale.
Celsius to Fahrenheit Calculator
Convert any Celsius temperature to Fahrenheit instantly. Includes Kelvin and a plotted conversion line so you can see the linear relationship.
Cent to Square Meter Converter
Convert cents to square metres, square feet, acres and hectares. 1 cent = 40.4686 m² — the standard land unit used in South India and Sri Lanka.
Centigrade to Celsius Converter
Convert centigrade to Celsius and learn why they are identical scales. Also converts to Fahrenheit, Kelvin and Rankine.
Centimeter Calculator
Convert centimeters to inches, feet, meters, millimeters, yards and miles instantly with a full reference table.
Cents to Dollars Calculator
Convert US cents to dollars instantly. Shows the decimal dollar amount, whole dollars and remaining cents.
Cents to Euros Calculator
Convert euro cents (the minor unit) to euros. Shows the decimal euro amount, whole euros and remaining cents.
CGS System of Units Calculator
Convert between CGS (centimetre-gram-second) and SI (metre-kilogram-second) units for length, mass, force, energy, pressure and more.
cm to Feet and Inches
Convert any height in centimetres to feet and inches. See feet, remaining inches, total inches and metres instantly.
cm to ft and in Converter
Convert centimetres to feet and inches, or feet and inches back to centimetres. Instant bidirectional cm ↔ ft + in converter.
CM to Inches Calculator
Convert centimeters to decimal inches, fractional inches (nearest 1/16") and feet + inches instantly.
CM to KM Calculator
Convert centimeters to kilometers instantly. Also shows meters, miles, feet and nautical miles.
CM to M Calculator
Convert centimeters to meters instantly. Also shows mm, km, inches and feet for a full reference.
CM to MM Calculator
Convert centimeters to millimeters instantly. Exact metric conversion: 1 cm = 10 mm, with a full reference.
Color Converter
Convert an RGB color (0–255 per channel) to HEX, HSL, HSV and CMYK — with a live color preview swatch.
Conversion Calculator
Convert any value between two units using a custom conversion factor. Enter the factor yourself for any unit pair not covered by a dedicated converter.
烹饪计量转换器
在茶匙、汤匙、液量盎司、杯、品脱、夸脱、毫升和升之间转换烹饪计量单位。
Coordinates Converter
Convert 2D coordinates between Cartesian (x, y) and polar (r, θ) form — both directions, with degrees and radians.
CPS Converter
Convert typing speed between characters per second (CPS), words per minute (WPM), CPM, and keystrokes per hour (KPH).
Crore to Lakh Calculator
Convert crore to lakh instantly. Also shows millions, billions and thousands. 1 crore = 100 lakh.
Crore to Million Calculator
Convert crore to million instantly. Also shows lakh, billion and trillion. 1 crore = 10 million.
Cubic Feet Calculator
Calculate cubic feet from length, width and height in feet. Instantly converts to cubic yards, cubic inches, cubic meters, liters and US gallons.
Cubic Feet to Cubic Meters Converter
Convert cubic feet to cubic meters instantly. Also converts to liters, US gallons, cubic inches, cubic yards and cubic centimetres.
Cubic Feet to Gallons Calculator
Convert cubic feet to US gallons, UK gallons, liters, quarts and pints instantly using the exact 1 ft³ = 7.48052 gal factor.
Cubic Feet to Pounds Calculator
Convert cubic feet to pounds (and kg, tons) for water, concrete, sand, soil, steel and more — choose a material or enter a custom density.
Cubic Inches to Gallons Calculator
Convert cubic inches to US gallons, UK gallons, liters, quarts and fluid ounces using the exact 231 in³ = 1 US gal definition.
Cubic Meter Calculator
Calculate cubic meters from length, width and height in meters. Converts to liters, cubic feet, cubic inches, cubic centimeters and gallons.
Cubic Meter to Ton Calculator
Convert cubic meters to metric tons, short tons and pounds for water, concrete, sand, steel and more — choose a material or enter a custom density.
Cubic Yards to Tons Calculator
Convert cubic yards to US short tons (and metric tons) for concrete, gravel, sand, topsoil, crushed stone and more using bulk density values.
Cups to Fluid Ounces Calculator
Convert US cups to fluid ounces instantly. Also shows tablespoons, teaspoons, pints, quarts, millilitres and litres.
Cups to Gallons Converter
Convert US cups to gallons, quarts, pints, fluid ounces, milliliters and liters. 16 US cups = 1 US gallon exactly.
Cups to Pints Converter
Convert US cups to pints. Also shows quarts, gallons, fluid ounces, millilitres and litres.
Cups to Quarts Converter
Convert US cups to quarts. Also shows pints, gallons, fluid ounces, millilitres and litres.
货币转换器
使用实时、每日更新的汇率在主要世界货币之间进行转换。
数据存储转换器
准确地转换字节、KB、MB、GB、TB 以及二进制 KiB、MiB、GiB 单位。
数据传输速率转换器
即时在比特每秒、kbit/s、Mbit/s、Gbit/s 以及字节、KB/s、MB/s、GB/s 之间转换数据传输速率。
数据传输时间计算器
计算数据集通过链路的实际传输时间,考虑协议/开销效率以获得有效吞吐量。
Day Converter
Convert days to seconds, minutes, hours, weeks, months and years — and back. Uses exact hour/minute/second factors and a 365.25-day average year.
dBm to Watts Converter
Convert dBm to watts, milliwatts and microwatts instantly. Used in RF, wireless, audio and optical power measurement.
Decagram to Gram Calculator (dag → g)
Convert decagrams to grams and other weight units — kg, mg, oz, lb — using the exact SI factor 1 dag = 10 g.
Decimal to Hexadecimal Converter
Convert any non-negative integer from decimal (base 10) to hexadecimal (base 16) with binary and octal for context.
Decimal to Octal Converter
Convert any non-negative decimal integer to octal (base 8), with binary triplet grouping and hex for context.
Decimeter to Meter Calculator (dm → m)
Convert decimetres to metres and seven other units — cm, mm, km, inches, feet, yards — using the exact SI factor 1 dm = 0.1 m.
Decimetre Conversion Calculator (dm)
Convert decimetres (dm) to and from millimetres, centimetres, metres, kilometres, inches, feet, yards, and miles.
Degrees Minutes Seconds (DMS) Calculator
Convert between decimal degrees and degrees–minutes–seconds (DMS) notation, plus radians and gradians. Ideal for GPS coordinates, surveying and navigation.
Degrees to Arc Seconds Converter
Convert an angle in degrees, arc minutes and arc seconds (DMS) to total arc seconds, decimal degrees and radians.
Degrees to Minutes Converter (Arcminutes & Arcseconds)
Convert decimal degrees to arcminutes and arcseconds. Also outputs radians, gradians and full DMS notation. Useful for GPS, astronomy and navigation.
密度转换器
在 kg/m3、g/cm3、g/ml、kg/L、lb/ft3 和 lb/in3 之间快速准确地转换密度,适用于科学和工程。
Dimensional Analysis Calculator
Chain up to three conversion factors to convert any unit step-by-step using the factor-label method.
Dimes to Dollars Calculator
Convert any number of dimes, quarters, nickels, pennies and half dollars to dollars — instant coin jar total.
Distance Converter
Convert between common distance units — mm, cm, m, km, inches, feet, yards, miles, nautical miles, light-years and AU.
下载时间计算器
根据文件大小和连接速度估算文件的下载时间,并以 hh:mm:ss 格式清晰显示结果。
Drops to mL Converter
Convert drops (gtt) to millilitres for standard, IV macrodrip, IV microdrip or essential-oil drop sizes. Also shows litres, teaspoons and tablespoons.
字节序转换器(字节交换)
交换 16/32/64 位十六进制值的字节顺序,在大端序和小端序之间转换。
Energy Conversion Calculator
Convert between energy units: Joules, kJ, MJ, kWh, Wh, calories, kcal, BTU, foot-pounds and ergs instantly.
能量转换器
在焦耳、千焦、卡路里、千卡、瓦时、千瓦时、英热单位、英尺磅和电子伏特之间转换能量。
Fahrenheit Calculator
Convert Fahrenheit to Celsius, Kelvin and Rankine instantly with exact formulas and a visual temperature scale.
Fahrenheit to Celsius Calculator
Convert Fahrenheit to Celsius instantly — also shows Kelvin and Rankine equivalents with the exact formula.
Feet and Inches Calculator
Convert a length in feet and inches to centimetres, metres, millimetres, yards and total inches. Handles any combination of feet and inches.
Feet Converter
Convert feet to meters, inches, centimeters, millimeters, yards, miles, kilometers, and nautical miles instantly with exact values.
Feet to Inches Calculator
Convert feet to inches instantly — 1 foot = 12 inches exactly. Also shows the result in centimetres and metres.
Feet to Metres Calculator
Convert feet to metres, centimetres, millimetres, inches, yards and kilometres instantly. 1 ft = 0.3048 m exactly.
Feet to Miles Calculator
Convert feet to miles, kilometres, metres, yards and nautical miles. 1 statute mile = 5,280 feet exactly.
Feet to Yards Conversion Calculator
Convert feet to yards, metres, centimetres and inches. 1 yard = 3 feet exactly. Shows whole yards plus any remaining feet.
Fluid Ounces to Pounds Converter
Convert US fluid ounces to pounds, ounces, grams, and kg for water, milk, oil, honey, and other substances by density.
Foot to Centimeter Converter
Convert feet and inches to centimetres instantly. 1 ft = 30.48 cm exactly. Also shows metres, millimetres and total inches.
Force Conversion Calculator
Convert force between Newton, pound-force, kilogram-force, kilonewton, kip, dyne, poundal and millinewton instantly.
力转换器
在牛顿、千牛顿、达因、磅力、千克力和盎司力之间快速准确地转换力。
频率转换器
即时在赫兹、千赫、兆赫、吉赫、太赫和转每分 (rpm) 之间转换频率。
燃油经济性转换器
在 L/100km、千米每升、美制英里每加仑和英制英里每加仑之间准确转换燃油经济性。
Gaj to Square Yard Converter
Convert gaj to square yards, square feet, square metres, marla, biswa, acres and hectares. 1 gaj = 1 square yard.
Gallon Calculator
Convert US liquid, US dry or Imperial gallons to litres, millilitres, quarts, pints, cups, fluid ounces and cubic units.
Gallons to Cubic Feet Calculator
Convert US liquid or Imperial gallons to cubic feet, cubic inches, cubic metres, litres and millilitres instantly.
Gallons to Cups Converter
Convert US or Imperial gallons to cups, pints, quarts, fluid ounces, tablespoons and teaspoons instantly.
Gallons to Grams Calculator
Convert US or Imperial gallons to grams, kilograms, ounces and pounds using density. Choose water, fuel, oil, honey and more.
Gallons to Kilograms Calculator
Convert US or imperial gallons to kilograms for water, gasoline, diesel, milk, ethanol, oil, honey and more.
Gallons to Pints Converter
Convert US or Imperial gallons to pints, quarts, cups, fluid ounces and litres with exact ratio-based conversions.
Gallons to Pounds Calculator
Convert US gallons to pounds and kilograms for water, gasoline, diesel, milk, oil, honey and more — or enter a custom density.
Gallons to Quarts Converter
Convert gallons to quarts, pints, cups and fluid ounces — for both US liquid and UK Imperial gallons — plus litres and millilitres.
Gallons to Tons Calculator
Convert US or imperial gallons to metric tons, US short tons and UK long tons for water, fuel, oil and other common liquids.
Gematria Calculator
Convert any English word or phrase to a gematria number value using Simple (A=1–Z=26), Reverse, or Reduced systems.
Gram to Liter Conversion Calculator
Convert grams to liters for water, milk, oil, honey and other liquids using each substance's density.
Grams to Calories Calculator
Convert grams of protein, carbohydrates, fat and alcohol to kilocalories using the Atwater energy factors.
Grams to Fluid Ounces Calculator
Convert grams to US fluid ounces for water, milk, flour, honey and more — density applied automatically per ingredient.
Grams to mL Converter
Convert grams to milliliters for water, ethanol, oil, glycerol, mercury and more — using each substance's density.
Convert grams to millilitres for water, flour, sugar, butter, oil, honey and more using each ingredient's density.
Grams to Ounces Converter
Convert grams to avoirdupois ounces, troy ounces, pounds and kilograms instantly with a reference weight scale.
Grams to Pounds Calculator
Convert grams to pounds (and ounces), or between any combination of grams, kilograms, ounces and pounds instantly.
Grams to Teaspoons Converter
Convert grams to US teaspoons for water, flour, sugar, salt, baking soda, honey and more using each ingredient's density.
格雷码转换器(二进制 ↔ 格雷码)
在标准二进制和反射格雷码之间转换,相邻值恰好只有一位不同。
Greek Gematria Calculator
Calculate the isopsephy (Greek gematria) value of any Greek word or phrase. Each letter maps to its Milesian numeral: Α=1, Ι=10, Ρ=100, Ω=800 and so on.
Hardness Conversion Calculator
Convert between Rockwell C, Vickers and Brinell hardness scales for steel using ASTM E140 interpolated lookup tables.
Hectares to Acres Converter
Convert hectares to acres (and to square meters, square feet, square miles, square yards) using the exact international conversion factor: 1 ha = 2.47105381 acres.
身高转换器(cm ↔ ft/in)
在厘米与英尺加英寸之间转换身高。切换方向以进行 cm → ft/in 或 ft/in → cm 转换,并显示米制数值。免费、即时且精确。
Height in Inches Calculator
Convert height from feet and inches or centimetres to total inches. Instantly see the equivalent in cm and metres.
HEX 转 RGB 颜色转换器
将十六进制颜色代码(#RGB 或 #RRGGBB)转换为红、绿、蓝通道值和 CSS rgb() 字符串。
Hour Converter
Convert hours to minutes, seconds, milliseconds, days, weeks, months and years instantly. Supports decimal hours (e.g. 1.5 h).
Hours to Days Calculator
Convert hours to days instantly. See full days, remaining hours, weeks, months and years — decimal input supported.
Hours to Seconds Converter
Convert hours to seconds, minutes, milliseconds and microseconds instantly. 1 hour = 3 600 seconds — decimal input supported.
Hours to Weeks Calculator
Convert hours to weeks with the exact full-weeks and remainder breakdown. 168 hours = 1 week. Decimal input supported.
Hours to Years Calculator
Convert hours to years, months, weeks and days. Uses the Gregorian average of 365.25 days per year (8 766 hours). Decimal input supported.
IEEE-754 浮点数转换器
将十进制数分解为 32 位(单精度)和 64 位(双精度)的 IEEE-754 符号位、指数和尾数位。
Imperial to Metric Conversion Calculator
Convert imperial units to metric: length (in/ft/mi), weight (lb/oz), volume (US gal/fl oz), temperature (°F), area, and speed.
Imperial Unit Converter
Convert between imperial (inches, feet, pounds, gallons, °F) and metric units instantly — all four measurement types in one tool.
Inch Converter
Convert inches to millimetres, centimetres, metres, feet, yards and miles instantly using exact SI definitions.
Inch to Meter Calculator
Convert inches to metres, centimetres, millimetres, feet and yards instantly using the exact 1 in = 0.0254 m definition.
Inch-Pounds to Foot-Pounds Calculator
Convert torque from inch-pounds (in·lb) to foot-pounds (ft·lb) and Newton-metres instantly. 12 in·lb = 1 ft·lb, exact.
Inch-Pounds to Newton-Metres Calculator
Convert torque from inch-pounds (in·lbf) to newton-metres (N·m). Also shows foot-pounds, kgf·cm and centinewton-metres.
Inches to Centimetres Calculator
Convert inches to centimetres instantly. 1 inch = 2.54 cm exactly. Also shows millimetres, metres and feet-and-inches.
Inches to Fraction Calculator
Convert decimal inches to the nearest fractional inch (halves, quarters, eighths, sixteenths, thirty-seconds, sixty-fourths) with the exact rounding error.
Inches to Yards Calculator
Convert inches to yards, feet and metres instantly. Exact: 1 yard = 36 inches. Shows whole yards plus remainder.
Joules to Volts Calculator
Convert energy in joules to voltage in volts using the formula V = E / Q (voltage = energy ÷ charge). Also supports conversion via current and time.
Katha to Square Feet Converter
Convert katha to square feet, square meters, square yards, acres and hectares. Supports regional values for West Bengal, Bihar, Assam and more.
Kelvin Converter
Convert any Kelvin temperature to Celsius, Fahrenheit, and Rankine instantly with exact formulas and a live conversion chart.
Kelvin to Celsius Calculator
Convert any Kelvin temperature to Celsius in one step. Includes a Fahrenheit bonus and a K → °C conversion chart.
Kelvin to Fahrenheit Calculator
Convert any Kelvin temperature to Fahrenheit using the exact two-step formula. Includes Celsius and a K → °F conversion chart.
kg to Gallons Calculator
Convert kilograms to US or UK gallons for water, milk, gasoline, oil and other liquids by selecting the substance density.
kg to lbs Converter
Convert kilograms to pounds (and back) with instant results in lbs, oz, stone, grams and tonnes.
kg to Liters Calculator
Convert kilograms to litres (and back) for water, milk, gasoline, oil and more by density. Also shows mL, gallons and cubic metres.
kg to mL Calculator
Convert kilograms to millilitres (and back) for water, milk, oil and other liquids. Also gives litres, fluid ounces, teaspoons and cups.
Kg to Ounce Converter (kg ↔ oz)
Convert kilograms to ounces (avoirdupois) or ounces to kilograms instantly, with grams and pounds too.
Kg to Stones Converter (kg ↔ st lb)
Convert kilograms to stones and pounds or stones/pounds to kilograms. Also shows total pounds.
kg/cm² to psi Converter
Convert kilogram-force per square centimetre (kgf/cm²) to psi, bar, kPa, MPa, atm, Pa and mmHg instantly.
Kilobytes to Megabytes Calculator (KB ↔ MB)
Convert kilobytes to megabytes and back — binary (IEC, ÷1024) or decimal (SI, ÷1000) — plus GB and TB.
Kilometer Calculator
Convert kilometres to miles, metres, feet, yards, inches, nautical miles and light-years — or convert any distance to kilometres.
Kilometer to Meter Conversion Calculator (km ↔ m)
Convert kilometres to metres and back. Also shows centimetres, millimetres, miles, feet and yards.
Kilometres to Feet Conversion Calculator
Convert kilometres to feet, inches, yards and miles. Uses the exact international foot (0.3048 m). 1 km = 3,280.84 feet.
Kilometres to Miles Calculator
Convert kilometres to miles instantly. Uses the exact international definition: 1 mile = 1.609344 km. Also shows metres, feet and nautical miles.
Knots to km/h Calculator
Convert knots to km/h, mph, m/s and ft/s. Exact conversion: 1 knot = 1.852 km/h. Also shows the Beaufort wind scale classification.
Knots to MPH Calculator
Convert knots (nautical miles per hour) to mph, km/h and m/s instantly. 1 knot = 1.150779 mph.
kPa Conversion Calculator
Convert kilopascals (kPa) to pascals, MPa, bar, atm, psi, mmHg, Torr, inHg and mbar — or convert any pressure unit to kPa.
kPa to ATM Conversion Calculator
Convert kilopascals (kPa) to standard atmospheres (atm) — plus Pa, bar, psi and mmHg. 1 kPa = 0.009869 atm.
kPa to mmHg Conversion Calculator
Convert kilopascals (kPa) to millimetres of mercury (mmHg) — plus Torr, atm, bar and psi. 1 kPa = 7.5006 mmHg.
kPa to PSI Conversion Calculator
Convert kilopascals (kPa) to psi (pounds per square inch) — plus atm, bar and mmHg. 1 kPa = 0.14504 psi.
ksi to MPa Conversion Calculator
Convert ksi (kilopounds per square inch) to MPa (megapascals) instantly. Also shows GPa, kPa, bar and psi equivalents.
ksi to psi Conversion Calculator
Convert ksi (kilopounds per square inch) to psi instantly. 1 ksi = 1000 psi exactly. Also shows MPa, kPa and bar.
Land Area Calculator
Convert land area between acres, hectares, square meters, square feet, sq km, sq miles, rai, cents and marla instantly.
Lat/Long to UTM Converter
Convert latitude and longitude (decimal degrees, WGS84) to UTM easting, northing, zone and band using the Transverse Mercator projection formula.
lbs to kg Converter
Convert pounds to kilograms instantly. Shows kg, g, oz, stones and tonnes — based on the exact 1 lb = 0.45359237 kg definition.
lbs to Newton Calculator
Convert a mass in pounds to gravitational force in newtons. Choose Earth, Moon or Mars gravity. Shows kN, kgf and dyne.
lbs to Pounds Converter
Convert common pounds (avoirdupois) to troy pounds and metric pounds. Shows troy ounces, grams and grains — different pound standards explained.
lbs to PSI Calculator
Calculate PSI from a force in pounds over a contact area in square inches. Also converts to kPa, bar, atm and MPa. Ideal for hydraulics and contact pressure.
lbs to Stone Converter
Convert pounds to stones and pounds remainder. Also shows kilograms, ounces and decimal stones. Used for body weight in the UK and Ireland.
Leet Speak Calculator
Convert normal text into leet speak (1337) by substituting letters with numbers and symbols — basic or advanced mode.
长度转换器
在米、千米、英里、英尺、英寸、码等单位之间转换——即时且准确。
列弗兑欧元换算器——官方固定汇率1.95583
按官方不可撤销的固定换算率1欧元 = 1.95583保加利亚列弗,在保加利亚列弗与欧元之间互换(依法规定的舍入方式)。
Light-Year Conversion Calculator
Convert light-years to kilometres, miles, astronomical units (AU), and parsecs — or convert any of those back to light-years.
Liters to Centiliters (cL) Converter
Convert litres to centilitres instantly — plus millilitres, US fluid ounces, cups and tablespoons. 1 L = 100 cL.
Liters to Pounds Calculator
Convert litres to pounds (and kg, g, oz) for water, milk, fuel, oil and more — using each liquid's actual density.
Litre to cc Calculator
Convert between litres, cubic centimetres (cc), millilitres and US gallons — plus fl oz and cups in one step.
Litres to Gallons Calculator
Convert litres to US liquid gallons, UK (imperial) gallons and US dry gallons. Also shows quarts, pints, fl oz and millilitres.
Lot Size to Acres Calculator
Convert a real-estate lot size from square feet, square meters, square yards, hectares or square miles to acres instantly.
Lot Size to Square Feet Calculator
Convert a real-estate lot size from acres, square meters, square yards, hectares or square miles to square feet.
Lowercase to Uppercase Converter
Instantly convert text to UPPERCASE, lowercase, Title Case, Sentence case, or alternating case with a character and word count.
m/s to km/h Calculator
Convert m/s to km/h instantly. 1 m/s = 3.6 km/h exactly. Also shows mph, knots and feet per second.
MB to GB Converter
Convert megabytes (MB) to gigabytes (GB) in both decimal (SI) and binary (IEC GiB) standards, plus KB, TB, KiB, MiB, TiB and bits.
Mbps Converter
Convert Mbps to MB/s, KB/s and Gbps, and calculate how long it takes to download or upload any file at your speed.
Mbps to Gbps Calculator
Convert network speed from Mbps to Gbps (÷1 000) and to MB/s, GB/s, Kbps, bps — with a step-by-step breakdown of all conversions.
mcg to mg Calculator
Convert between micrograms (mcg/µg) and milligrams (mg) instantly. 1 mg = 1 000 mcg. Works in both directions.
mcg to mL Calculator
Calculate how many mL to draw from a solution to deliver a dose in micrograms (mcg) — given drug amount and total volume.
Measurement Converter
Convert between metric and imperial units for length, mass, area, volume, speed and temperature. Instant, precise output.
Mesh to Micron Converter
Convert US Standard mesh numbers to microns (µm), mm and inches using ASTM E11 sieve data, or convert particle sizes back to the nearest mesh.
Meter Conversion Calculator
Convert meters to feet, miles, kilometers, inches, yards and nautical miles — or from any unit back to meters.
Meter to Mile Conversion Calculator
Convert meters to miles instantly. Also shows kilometers, feet, yards and nautical miles. 1 mile = 1609.344 m exactly.
Meters to Feet Calculator
Convert meters to feet and inches instantly. Also shows yards, miles, cm and mm. 1 meter = 3.28084 feet exactly.
Metres to Feet Calculator
Convert metres to feet, feet and inches, yards, centimetres and millimetres instantly with exact conversion factors.
Metric Converter
Convert between all metric units for length (mm→km), mass (mg→t) and volume (mL→kL) using SI prefix factors.
Metric to Imperial Conversion Calculator
Convert metric units (cm, kg, mL, °C) to imperial units (inches, pounds, fl oz, °F) — length, weight, volume and temperature in one tool.
Metric to Inches Calculator
Convert metric lengths (mm, cm, m, km) to inches and feet. 1 inch = 25.4 mm exactly. Also shows yards and miles.
Metric to SAE Calculator
Convert metric wrench and socket sizes (mm) to the nearest SAE (fractional inch) equivalent. Shows deviation and adjacent SAE sizes.
Metric to Standard Converter
Convert metric units (km, kg, L, °C, km/h) to US standard / imperial units — miles, pounds, gallons, Fahrenheit, and mph.
mg to cc Calculator
Convert milligrams to cubic centimetres (cc) using substance density. Choose a preset or enter a custom density.
mg to lbs Calculator
Convert milligrams to pounds (lb), ounces, grams, and kilograms using exact avoirdupois conversion factors.
mg to mL Calculator
Convert milligrams to millilitres using substance density. Includes presets for water, saline, ethanol, milk, oil, honey, and blood.
mg to Tablespoon Converter
Convert milligrams to US tablespoons using substance density. Includes presets for water, oil, honey, milk, maple syrup, and butter.
mg to Teaspoon Converter
Convert milligrams to teaspoons for water, sugar, salt, flour, honey and more — instantly, based on substance density.
Micrometer Conversion Calculator
Convert micrometres (µm) to nanometres, millimetres, centimetres, metres, inches, feet, mils and angstroms — all conversions exact.
Micron to Mil Conversion Calculator
Convert microns (µm) to mils (thou) and back — 1 mil = 25.4 µm exactly. Enter either unit for the full conversion.
Mil Conversion Calculator
Convert mils (thousandths of an inch) to micrometers, millimeters, centimeters, meters and inches instantly.
Mil to Inch Conversion Calculator
Convert mils (thousandths of an inch) to decimal inches, fractional inches, feet, mm and µm. Exact: 1 mil = 0.001 inch.
Mil to mm Conversion Calculator
Convert mils (thousandths of an inch) to millimeters and micrometers. Exact: 1 mil = 0.0254 mm = 25.4 µm.
Mile Conversion Calculator
Convert miles to kilometers, meters, feet, yards, nautical miles and centimeters instantly with exact international conversion factors.
Millimeter Calculator
Convert millimeters to inches, centimeters, meters, micrometers, feet, yards and miles instantly with exact conversion factors.
Million to Billion Calculator
Convert any number of millions to billions, trillions, and the full raw figure instantly.
Million to Lakh Calculator
Convert millions to lakhs instantly. 1 million = 10 lakh. Also shows crores, thousands and the full numeric value.
Million to Thousand Converter
Convert millions to thousands instantly. 1 million = 1,000 thousand. Also shows billions, lakhs and the full numeric value.
Milliseconds Converter
Convert milliseconds to seconds, minutes, hours, days, microseconds, and nanoseconds instantly.
Milliseconds to Seconds Conversion Calculator
Convert milliseconds (ms) to seconds, minutes, hours, microseconds and nanoseconds. 1 ms = 0.001 s exactly.
Minute Converter
Convert minutes to seconds, milliseconds, hours, days, weeks, months and years instantly. Supports decimal minutes.
Minutes to Days Calculator
Convert any number of minutes to days — showing decimal days plus the exact whole-days, remaining hours and remaining minutes breakdown.
Minutes to Decimal Conversion
Convert hours and minutes (HH:MM) to decimal hours for timesheets, payroll or scheduling. Example: 1 h 30 min = 1.5 h.
Minutes to Seconds Converter
Instantly convert minutes to seconds, hours, days and milliseconds — any decimal value supported.
Minutes to Years Conversion Calculator
Convert minutes to years, months, weeks, days, hours and seconds with a detailed mixed-unit breakdown.
mL to cc Converter
Convert millilitres (mL) to cubic centimetres (cc or cm³) instantly — 1 mL = 1 cc by definition. Also shows litres, cubic inches and US/UK fluid ounces.
mL to Cups Calculator
Convert millilitres to cups (US customary, US legal, metric or imperial) and get the nearest kitchen fraction like ¾ cup. Reverse conversion included.
mL to kg Calculator
Convert millilitres to kilograms using density. Choose water, milk, oil, honey, alcohol or enter a custom density.
mL to lbs Calculator
Convert millilitres to pounds using density. Choose water, milk, oil, honey, alcohol or enter a custom density.
mL to oz Converter
Convert millilitres to US or UK fluid ounces, or to weight ounces using substance density. Includes tablespoons, cups and pounds.
mL to Tablespoon Converter
Convert millilitres to tablespoons (US, metric, Australian or UK) and vice-versa. Includes cross-reference for all four tablespoon standards.
mL to tsp Converter
Convert millilitres to teaspoons and tablespoons for US, Metric/Australian or UK measurements. 1 US tsp = 4.929 mL, 1 metric tsp = 5 mL.
mL to µL Conversion Calculator
Convert millilitres to microlitres (µL), nanolitres, picolitres, litres and US fluid ounces. 1 mL = 1,000 µL exactly.
MM Millimeters Calculator
Convert inches, feet, yards, centimeters, meters, kilometers or micrometers to millimeters instantly with exact conversion factors.
MM to Feet Converter
Convert millimeters to feet (decimal and feet-and-inches). Also shows equivalent inches, centimeters and meters.
MM to Inches Conversion Calculator
Convert millimeters to decimal inches and the nearest 1/16-inch fraction. Also shows feet, centimeters and meters.
MM to KM Conversion Calculator
Convert millimeters to kilometers and other units — meters, centimeters, miles and feet — using exact SI-defined factors.
MM to Meters Conversion Calculator
Convert millimeters to meters — plus centimeters, kilometers, inches and feet — using exact SI definitions.
mmHg to atm Conversion Calculator
Convert millimeters of mercury (mmHg) to standard atmospheres (atm) and other pressure units — Pa, kPa, bar and psi.
Convert mmHg (millimetres of mercury) to atm, Pa, kPa, bar, psi, inHg, Torr and mbar — or convert any pressure unit to mmHg.
Months to Years Calculator
Convert any number of months to years (and remaining months), plus total weeks, days and hours using average Gregorian calendar lengths.
MPa Conversion Calculator
Convert megapascals (MPa) to psi, bar, kPa, atm, GPa, Torr, mmHg and more — or convert any pressure unit to MPa.
MPa to PSI Conversion Calculator
Convert megapascals (MPa) to psi instantly. 1 MPa = 145.0377 psi. Also shows bar, kPa, atm and Pa.
MPa to PSIG Conversion Calculator
Convert MPa (absolute) to psig (gauge pressure in psi). 1 MPa abs ≈ 130.34 psig at standard atmosphere.
N·m to ft·lb Calculator
Convert torque between Newton-meters and foot-pounds in both directions. Essential for automotive, fastener, and engineering work.
N·m to in·lb Calculator
Convert torque between Newton-meters and inch-pounds in both directions. Used for small fasteners, electronics, and bicycle components.
Natural Gas Converter
Convert natural gas volume (cubic feet or cubic metres) to BTU, kWh, therms, MJ, GJ, and MMBtu using the standard higher heating value.
Newton to Joules Calculator
Convert newtons and metres to joules: calculate work/energy (W = F × d) and convert the result to kJ, calories, kcal, watt-hours, and foot-pounds.
Newton-Meter Calculator
Convert torque between Newton-meters, foot-pounds, inch-pounds, kgf·m and Newton-centimeters instantly.
Nickels to Dollars Calculator
Convert any number of nickels to dollars and cents instantly. Also shows equivalent pennies, dimes and quarters.
nm Converter
Convert nanometres to micrometres, millimetres, metres, angstroms and picometres — or convert any of those back to nm.
nm to m Conversion Calculator
Convert nanometres to metres (and metres to nanometres) instantly. Shows µm, mm, cm, and Å equivalents with a visible-light context scale.
在二进制、八进制、十进制和十六进制之间转换任意整数。输入一个值,选择它的进制,即可即时查看全部四种表示形式。
Number to Billion Converter
Convert any number to billions, millions, trillions and thousands instantly — with scientific notation and a full step-by-step breakdown.
Number to Million Calculator
Convert any number to millions, billions, trillions and thousands instantly — just divide by 1,000,000.
Ounce to kg Converter
Convert ounces to kilograms instantly. Supports both avoirdupois oz (everyday weight) and troy oz (precious metals). Also shows grams, pounds and stones.
Ounces to Cups Calculator
Convert US fluid ounces to cups, tablespoons, teaspoons, pints, quarts and millilitres instantly.
Ounces to Grams Converter
Convert ounces (avoirdupois) to grams, kilograms, milligrams and pounds with exact conversion factors.
Ounces to Pounds Converter
Convert ounces to pounds, kilograms, grams and stones using exact avoirdupois conversion factors.
Oz to cc Converter
Convert fluid ounces to cubic centimetres (cc) for medical, lab, and cooking use — cc equals mL exactly.
Oz to mL Converter
Convert fluid ounces to millilitres (or mL to fl oz) for US and UK imperial measurements instantly.
Pa to PSI Converter
Convert pressure between Pascals, PSI, kPa, MPa, bar, and atmospheres instantly.
Paper Quantity Calculator
Calculate how many sheets of paper and reams to buy for a print job — supports duplex printing and multiple paper sizes.
Pascal Conversion Calculator
Convert pascals (Pa) to kPa, MPa, bar, atm, psi, Torr, mmHg, inHg, hPa and more — or convert any pressure unit to pascals instantly.
Pennies to Dollars Calculator
Convert any number of US pennies (cents) to dollars instantly. Shows whole dollars, remaining cents, and the decimal dollar amount.
Pint to Pound Calculator
Convert US or Imperial pints to pounds (lb) for water, milk, oil, honey and more — using each liquid's density.
Pints to Cups Converter
Convert pints to cups instantly — US or Imperial. 1 pint = 2 cups in both systems; also shows fluid ounces, tablespoons, teaspoons, quarts and gallons.
Pints to Gallons Converter
Convert pints to gallons — US or Imperial. 8 pints = 1 gallon in both systems; also converts to quarts, cups, fluid ounces and litres.
Pixels to Inches Calculator
Convert pixels to inches, centimetres and millimetres using a resolution (DPI). Works for screens, print and graphic design.
Pounds and Ounces Calculator
Convert pounds and ounces to kilograms, grams, stones and total ounces. Enter lb + oz together for a combined weight.
Pounds to Grams Calculator
Convert pounds to grams, kilograms, ounces, milligrams and stones. Uses the exact avoirdupois definition: 1 lb = 453.59237 g.
Pounds to Grams Calculator (lbs to g)
Convert pounds to grams instantly using the exact factor 1 lb = 453.59237 g. Also converts to kg, mg, oz and stones.
Pounds to lbs Calculator
Convert kilograms, grams, ounces, stones or metric tons to pounds (lbs). Explains that "lb" and "lbs" are both abbreviations for pounds.
Pounds to Ounces Converter
Convert pounds to ounces instantly. Also shows grams, kilograms and stones. Uses the exact 1 lb = 16 oz (avoirdupois) definition.
Pounds to Stone Calculator
Convert pounds to stones and pounds. Shows whole stones, remaining pounds and ounces, kilograms and total ounces. 1 stone = 14 lb.
Power Conversion Calculator
Convert power between watts, kilowatts, megawatts, mechanical and metric horsepower, BTU/h, ft-lbf/s, cal/s and kcal/h. All results at once.
功率转换器
在瓦特、千瓦、兆瓦、马力、公制马力、英热单位每小时和英尺磅每秒之间转换功率。
PPM Calculator
Convert parts per million (ppm) to ppb, ppt, percent, per mille, mg/kg, mg/L and μg/L — and back from any of those units.
PPM to mg/L Converter
Convert parts per million (ppm) to mg/L, μg/L, ng/L, and g/L with optional density correction for non-water solutions.
压强转换器
在帕斯卡、千帕、兆帕、巴、psi、大气压、mmHg 和托之间转换压强——快速且准确。
Pressure Unit Conversion Calculator
Convert pressure between Pa, kPa, MPa, hPa, bar, psi, atm, mmHg, Torr and inHg — with all equivalent values shown at once.
PSI Conversion Calculator
Convert PSI (pounds per square inch) to bar, kPa, MPa, Pa, atm, mmHg, inHg, Torr and psf — or convert any pressure unit back to psi.
PSI to ATM Conversion Calculator
Convert psi (pounds per square inch) to atm (standard atmospheres) — plus bar, kPa and mmHg. 1 atm = 14.6959 psi.
PSI to GPM Calculator
Calculate water flow rate (GPM) from pressure (PSI) and orifice diameter using the standard discharge formula Q = 29.84 × Cd × d² × √P.
PSI to Inches of Water Conversion Calculator
Convert psi (pounds per square inch) to inches of water column (inH₂O) — plus mmH₂O, Pa and inHg. 1 psi = 27.6807 inH₂O.
PSIG to PSIA Conversion Calculator
Convert PSIG (gauge pressure) to PSIA (absolute pressure) by adding atmospheric pressure. Adjusts for altitude using the ISA model.
PX to EM Calculator
Convert pixel values to em, rem, pt, and % CSS units instantly. Set a custom parent or root font size for accurate results in any component.
Quantity Converter
Convert between counting units: units, pairs, dozens, baker's dozens, scores, gross and great gross — all equivalents shown at once.
Quarters to Dollars Calculator
Convert any number of US quarters (25¢ coins) to dollars and cents. Shows whole dollars, leftover cents, and equivalent dimes and nickels.
Quarts to Cups Converter
Convert US quarts to cups instantly — plus pints, fluid ounces, milliliters and liters. 1 quart = 4 cups.
Quarts to Gallons Converter
Convert US quarts to gallons in one step — plus pints, fluid ounces and liters. 4 quarts = 1 gallon.
Quarts to Pounds Calculator
Convert US quarts to pounds for water, milk, oil, honey, flour, sugar and more. Volume × density = mass.
Radioactivity Converter
Convert radioactivity between becquerel, curie, millicurie, microcurie, nanocurie, picocurie and rutherford — instant, accurate unit conversion.
RGB 转 HEX 颜色转换器
将红、绿、蓝值(0-255)转换为 #RRGGBB 十六进制代码以及可直接使用的 CSS rgb() 字符串。
RGB 转 HSL 颜色转换器
将 RGB 颜色通道转换为 HSL(色相度数、饱和度和亮度百分比),便于颜色调整。
RMS to Watts Calculator
Convert RMS voltage and RMS current to real power in watts (W), apparent power (VA) and reactive power (VAR) for AC circuits.
罗马数字转换器
在数字与罗马数字之间双向转换(1–3999),采用标准的减法记数规则。
Scale Conversion Calculator
Convert between real-world dimensions and scaled model or drawing dimensions for any 1:X scale ratio.
Seconds Converter
Convert any number of seconds to minutes, hours, days, weeks, months, years, milliseconds and microseconds instantly.
Seconds to Days Converter
Convert seconds to days instantly — see whole days plus the remaining hours, minutes and seconds, with hours, minutes and weeks also shown.
Seconds to Hours Converter
Convert seconds to hours instantly — get the exact decimal result plus the H:M:S breakdown.
Seconds to Minutes Converter
Convert seconds to minutes instantly — get the exact decimal minutes and the M:S breakdown.
Seconds to Years Converter
Convert any number of seconds to years — with a full Y:D:H:M:S breakdown and total days, hours, and minutes.
速度转换器
在 m/s、km/h、mph、节和英尺每秒之间快速准确地转换。
Square Centimeters to Square Millimeters Converter (cm² → mm²)
Convert square centimetres to square millimetres instantly. 1 cm² = 100 mm² because area scales as the square of the linear factor (1 cm = 10 mm).
Square Feet Converter
Convert square feet to square metres, square inches, yards, acres, hectares, km², and square miles.
Square Feet to Acres Converter
Convert square feet to acres (and hectares, m², sq yards, sq miles) instantly. 1 acre = 43,560 sq ft.
Square Inches to Square Feet Converter
Convert square inches to square feet instantly. Also shows the equivalent in square centimetres, square metres, and square yards.
Square Meter Converter
Convert square metres to square feet, square inches, square yards, square centimetres, hectares, acres, square kilometres and square miles instantly.
Square Meters to Square Feet Converter
Convert square metres to square feet (or feet to metres) instantly. Bidirectional — fill either box. Also shows square yards and square inches.
Square Miles to Square Kilometres Converter
Convert square miles to square kilometres (or km² to mi²) instantly. Bidirectional. Also shows hectares, acres and square metres.
Square Yard Converter
Convert square yards to square meters, square feet, acres, hectares and back — with an instant full conversion table.
Stone to kg Calculator (st & lb → kg)
Convert stones and pounds to kilograms. Uses the exact definition: 1 stone = 14 lb = 6.35029318 kg.
Stone to Pounds Calculator (st → lbs)
Convert stones and pounds to total pounds, kilograms and ounces. 1 stone = 14 lbs exactly — no rounding.
Tablespoons to Grams Calculator
Convert US tablespoons to grams for flour, sugar, butter, honey, salt and 20 other common ingredients using ingredient-specific densities.
Tablespoons to mL Calculator
Convert tablespoons to millilitres for US (14.79 mL), metric (15 mL), UK (17.76 mL) and Australian (20 mL) tablespoon standards.
Teaspoons to Grams Calculator
Convert teaspoons to grams for sugar, salt, flour, butter, honey and 14 other common cooking and baking ingredients.
温度转换器
使用精确公式即时转换摄氏度、华氏度、开尔文和兰氏度。
时间转换器
即时在纳秒、微秒、毫秒、秒、分钟、小时、天、周、月和年之间转换时间。
Time Unit Converter
Convert any time duration between nanoseconds, milliseconds, seconds, minutes, hours, days, weeks, months and years instantly.
扭矩转换器
在牛顿米、千牛顿米、磅英尺、磅英寸和千克力米之间准确转换扭矩。
Torque to Horsepower Calculator
Convert engine torque and RPM to horsepower, kilowatts and metric PS — enter Nm or lb-ft plus engine speed.
Torr to atm Calculator
Convert Torr to atmospheres (atm) and vice versa — plus Pa, kPa, bar and psi. 1 atm = 760 Torr exactly.
tsp to mL Converter
Convert teaspoons to millilitres for US, Metric/Australian or UK measurements. 1 US tsp = 4.929 mL, 1 metric tsp = 5 mL, 1 UK tsp ≈ 5.919 mL.
Unicode Text Calculator
Convert any text to Unicode code points (U+XXXX hex, decimal or binary) and see the UTF-8 byte count, character count and script distribution.
Unix Time Calculator
Convert a Unix timestamp (seconds since 1970-01-01 UTC) to a human-readable UTC date and time, and see days, weeks, and years elapsed.
Uppercase to Lowercase Converter
Convert any text from uppercase (or mixed case) to all lowercase instantly, with a character-type breakdown.
视频码率与文件大小计算器
根据码率和时长(可选音频轨道)估算视频文件大小,或反向求解所需码率。
Volume Conversion Calculator
Convert volume between 20 metric and US/imperial units — liters, gallons, cups, fluid ounces, cubic feet and more.
体积转换器
在升、毫升、立方米、美制加仑、夸脱、品脱、杯、液量盎司、汤匙和英制加仑之间转换体积。
WCAG 颜色对比度计算器
检查两个十六进制颜色之间的对比度,以及是否符合 WCAG AA/AAA 对普通文本和大文本的要求。
Weeks to Months Calculator
Convert weeks to months, days and years using the average Gregorian month — shows whole months plus the remaining fractional part.
Weeks to Years Converter
Convert weeks to years, months, days, hours and minutes. Uses the Gregorian average of 52.1775 weeks per year.
重量与质量转换器
快速准确地转换千克、克、磅、盎司、英石和吨。
Weird Units Calculator
Convert any distance to obscure and unusual units: smoots, cubits, furlongs, hands, fathoms, chains, leagues and light years.
Yard Conversion Calculator
Convert yards to metres, centimetres, feet, inches, miles, furlongs and more using exact 1959 SI definitions.
Yard to Meter Conversion Calculator
Convert yards to meters, centimeters, millimeters, kilometers, feet and inches instantly using the exact 1959 international yard definition.
Yard to Mile Converter
Convert yards to miles, furlongs, feet, meters and kilometers. 1 mile = 1,760 yards exactly (1959 international definition).
Yards to Meters Calculator
Convert yards to meters or meters to yards instantly. 1 yard = 0.9144 m (exact). Includes feet, cm and km. Switch direction with one click.
Years to Decades Calculator
Convert years to decades, centuries, millennia, months, weeks, days and hours instantly. Supports decimal year inputs.
10/1 ARM Calculator
Calculate monthly payments, balance at reset and total interest for a 10/1 ARM — fixed for 10 years, then adjusting annually.
12-Hour Shift Calculator
Calculate weekly, monthly and annual gross pay for 12-hour shift workers — handles night-shift differential and daily or weekly overtime rules.
28/36 Rule Calculator
Check if your housing and debt payments meet the 28/36 mortgage qualification rule — max 28 % of income on housing, 36 % on all debt.
3× Rent Rule Calculator
Use the 3× income rule to find your maximum affordable rent, check if your income qualifies, or find the income needed for a given rent.
3D Printer Buy vs Outsource Calculator
Compare the total cost of buying a 3D printer against outsourcing prints to a service over any time horizon, with breakeven analysis.
401(k) Calculator
Project your 401(k) balance from salary, contribution %, employer match and expected return. Includes employer match modelling.
403(b) Calculator
Project your 403(b) retirement balance for teachers, nurses and non-profit employees, including the 15-year catch-up rule.
50/30/20 Rule Calculator
Split your after-tax income into needs (50%), wants (30%) and savings (20%) using the 50/30/20 budgeting rule — fully adjustable percentages.
529 College Savings Calculator
Project your 529 college savings plan balance from current balance, monthly contributions and expected return.
70/20/10 Rule Money Calculator
Split your monthly take-home pay into 70% living expenses, 20% savings and 10% giving or debt using the 70/20/10 budget rule.
Absence Rate Calculator
Calculate the employee absence rate as a percentage of scheduled working days — for individuals or teams over any period.
Accounting Profit Calculator
Calculate accounting profit = revenue minus all explicit costs (COGS, operating, admin, depreciation). Shows gross profit and margin.
Accrual Ratio Calculator
Calculate the accrual ratio (cash-flow and balance-sheet based) to assess earnings quality. High ratios may flag aggressive accounting.
Accumulated Depreciation Calculator
Calculate accumulated depreciation and current book value using straight-line, double-declining or 150% declining-balance methods.
Actual Cash Value Calculator
Calculate the actual cash value (ACV) of an item after depreciation — used by insurers to determine claim payouts.
ADR Calculator
Calculate the Average Daily Rate (ADR) for a hotel or rental property, plus occupancy rate and RevPAR from total room revenue.
AFFO Calculator
Calculate AFFO, FFO, AFFO per share, and P/AFFO for REITs — the key metrics for evaluating real estate investment trust cash flow.
AFN Calculator
Calculate Additional Funds Needed (AFN) for financial planning: how much external financing a company must raise to support its projected sales growth.
After-Tax Cost of Debt Calculator
Calculate the after-tax cost of debt using Kd × (1 − T). Enter the pre-tax interest rate and corporate tax rate to find the effective borrowing cost.
AGI Calculator
Calculate your US Adjusted Gross Income (AGI) by subtracting above-the-line deductions from total gross income.
Alabama Income Tax Calculator 2025
Estimate your 2025 Alabama state income tax — including the federal tax deduction, standard deductions, exemptions, and FICA withholding.
Alternative Minimum Tax (AMT) Calculator
Estimate your US Alternative Minimum Tax for 2024 — enter taxable income, AMT preferences, filing status and regular tax.
American Rescue Plan Calculator
Estimate your 2021 third Economic Impact Payment under the American Rescue Plan Act based on AGI, filing status, and dependents.
贷款分期摊还计算器
根据贷款金额、利率和期限计算每月还款额、总利息和完整的还清成本,并附带第一年的分期摊还表。
Annual Income Calculator
Convert any pay period (hourly, daily, weekly, monthly) to annual income, and see the equivalent across all periods.
Annual Pay Calculator
Calculate total annual pay from base salary, bonus percentage, overtime hours, and other income sources.
Annual Salary Calculator
Convert hourly, daily, weekly, bi-weekly or monthly pay to an annual salary — with full per-period breakdown.
Annual Salary to Hourly Rate Calculator
Convert your annual gross salary to an equivalent hourly rate — adjust for hours per week and paid time off.
Annual to Monthly Salary Calculator
Convert an annual gross salary to monthly, bi-weekly, weekly, daily and hourly equivalents instantly.
Annualized Rate of Return Calculator (CAGR)
Calculate the compound annual growth rate (CAGR) from a starting value, ending value and holding period in years.
Annuity Calculator
Calculate the future value of an annuity: how much regular deposits grow with compound interest over time.
Annuity Payout Calculator
Calculate the periodic payout from an annuity: how much regular income a lump sum generates at a given interest rate over a set term.
Annuity Present Value Calculator
Calculate the present value of an ordinary annuity or annuity due — the single lump sum today equal to a stream of equal future payments.
APC Calculator
Calculate Average Propensity to Consume (APC) and Average Propensity to Save (APS) from income and spending.
Appreciation Calculator
Calculate how much an asset (property, investment, collectible) will be worth after compound annual appreciation over any time horizon.
APR Calculator
Calculate the true Annual Percentage Rate (APR) of a loan including upfront fees, monthly payment, and total interest cost.
APY Calculator
Calculate Annual Percentage Yield (APY) from a nominal interest rate and compounding frequency, including continuous compounding.
AR Days Calculator
Calculate Accounts Receivable Days (DSO) and the AR turnover ratio from your AR balance, revenue and credit-sales percentage.
ARM Mortgage Calculator
Calculate ARM mortgage payments: initial fixed-rate payment, projected payments after each rate adjustment, maximum payment and total interest.
ARV Calculator
Calculate After Repair Value (ARV), net profit and ROI for fix-and-flip real estate. Includes the 70% rule maximum offer price.
Atal Pension Yojana (APY) Calculator
Estimate monthly APY contributions needed to receive a guaranteed pension of ₹1,000–₹5,000/month at age 60 under India's Atal Pension Yojana scheme.
Attrition Rate Calculator
Calculate employee attrition rate and retention rate from headcount and departures — useful for HR planning and workforce analysis.
Australia Income Tax Calculator
Estimate Australian resident income tax for FY 2024-25 with the Stage 3 modified brackets, Low Income Tax Offset (LITO) and Medicare Levy.
Auto Lease Calculator
Calculate your monthly car lease payment from MSRP, residual value, APR and term using the standard money-factor formula.
Auto Loan Calculator
Calculate monthly car loan payments, total interest, and full cost of ownership — with down payment, trade-in, and sales-tax support.
AVC Calculator
Calculate Average Variable Cost (AVC = TVC ÷ Q) and optionally Average Fixed Cost and Average Total Cost from your production figures.
Average Collection Period Calculator
Calculate average collection period (DSO) and receivables turnover ratio from accounts receivable and net credit sales.
Average Fixed Cost Calculator
Calculate average fixed cost per unit and see how AFC falls as production rises — a core concept in cost accounting and break-even analysis.
Balance Transfer Calculator
Calculate how much interest you save by transferring a credit card balance to a lower-rate card, after accounting for the transfer fee.
Balloon Payment Calculator
Calculate the balloon payment, monthly instalment, and total interest on a balloon mortgage or loan using a standard amortization schedule.
Bank Reconciliation Calculator
Reconcile your bank statement with your cash book — find deposits in transit, outstanding checks, bank charges and NSF adjustments.
Basis Point Calculator
Convert basis points to percentage, decimal and currency change instantly. 1 bp = 0.01%. Essential for interest rates and yield spreads.
Bi-Weekly Mortgage Payment Calculator
See how bi-weekly mortgage payments (26 half-payments/year) reduce total interest paid and shorten your loan term.
Biden Tax Plan Calculator
Estimate federal income tax under the Biden FY2025 budget proposal (39.6% top rate) vs current TCJA 2024 brackets.
Bike EMI Calculator
Calculate your monthly EMI for a bike or scooter loan — enter price, down payment, interest rate and tenure to see total interest and balance curve.
Bill Rate Calculator
Calculate the bill rate (client charge) from pay rate, overhead burden and target profit margin or markup for staffing and consulting.
Billable Hours Calculator
Calculate weekly, monthly and annual income from hourly rate, working hours, days per week and billable efficiency percentage.
Bitcoin ETF Calculator
Calculate the expected return from a Bitcoin ETF investment, accounting for annual expense ratio fee drag against a BTC price target over any holding period.
Biweekly Mortgage Calculator
See how biweekly mortgage payments cut your loan term and total interest — enter loan amount, rate and term to compare.
Biweekly Pay Calculator
Estimate your biweekly take-home pay after federal tax, state tax, FICA and other deductions from your annual salary.
Black Friday Calculator
Calculate your final Black Friday price after a percentage discount and sales tax — see exactly how much you save.
Black-Scholes Calculator
Price European call and put options using the Black-Scholes model — includes delta, gamma, vega and theta Greeks.
Blended Rate Calculator
Calculate the blended (weighted average) interest rate across multiple loans or mortgages, weighted by each loan's outstanding balance.
Boat Loan Calculator
Calculate your monthly boat loan payment, total interest and full cost of ownership from price, down payment, rate and term.
Bond Convexity Calculator
Calculate bond price, modified duration and convexity for any coupon bond — see the curved price-yield relationship and measure interest-rate sensitivity.
Bond Current Yield Calculator
Calculate the current yield of a bond — annual coupon income divided by current market price — and see whether it trades at premium or discount.
Calculate a bond's current yield — annual coupon income as a percentage of the current market price — and see the premium or discount to par value.
Bond Equivalent Yield Calculator
Convert a T-bill discount rate into a bond-equivalent yield (BEY) for fair comparison with semi-annual coupon bonds.
Bond Price Calculator
Calculate the fair price of a coupon bond given face value, coupon rate, required yield and maturity using present-value discounting.
Bond YTM Calculator
Calculate the yield to maturity (YTM) of a coupon bond using Newton-Raphson iteration on the full present-value pricing equation.
Bounce Rate Calculator
Calculate your website bounce rate and engagement rate from total sessions and single-page bounces, with industry benchmark comparison.
Bradford Factor Calculator
Calculate the Bradford Factor (S² × D) to measure how disruptive an employee's absence pattern is compared to total days lost.
盈亏平衡计算器
根据你的固定成本、单价和单位变动成本,求出以单位数和收入表示的盈亏平衡点。
Brexit Trade Cost Calculator
Estimate the additional cost of post-Brexit UK-EU trade: import/export tariffs, non-tariff barriers and customs admin by sector.
Budget Calculator
Enter monthly income and expenses to instantly calculate your savings, savings rate, and see a visual breakdown of where your money goes.
Build Back Better Calculator
See how long it takes to rebuild your savings after a financial setback using regular contributions and compound investment growth.
Build or Buy Calculator
Compare the total cost of building something in-house versus buying or licensing an existing solution over a multi-year time horizon.
保加利亚薪资计算器2026
2026年保加利亚税后薪资计算器:10%统一所得税、含应保险收入上限的社会保险缴款,结果以列弗和欧元双币种显示(官方固定汇率)。
Burn Rate Calculator
Calculate your startup's gross and net burn rate, and how many months of runway remain before cash runs out.
Burndown Chart Calculator
Calculate sprint burndown: ideal vs. actual velocity, remaining story points, projected completion date, and whether the team is on track.
Business Budget Calculator
Calculate gross profit, operating profit, and profit margins from revenue, COGS, fixed costs, variable costs, and other expenses.
Business Loan Calculator
Calculate the monthly repayment, total interest, and total cost of a business loan given the amount, annual rate, and term.
Business Valuation Calculator
Estimate a business value using three methods: EBITDA multiple, revenue multiple, and P/E ratio — with an average across all three.
Buying Power Calculator
See how inflation erodes purchasing power over time: enter an amount, annual inflation rate, and years to find real value and equivalent future cost.
CAGR Calculator
Calculate CAGR from beginning and ending values over any number of years — the smoothed annual growth rate for investments, revenue or any metric.
California Overtime Calculator
Calculate California overtime pay under Labor Code § 510 — daily OT (1.5× after 8 hrs, 2× after 12), weekly OT and 7th-day rules.
California Stimulus Check Calculator
Estimate your California Middle Class Tax Refund (MCTR) payment based on your 2020 CA AGI, filing status and dependents.
California Tax Calculator
Estimate your 2024 California state income tax, SDI deduction, effective and marginal rates, and after-tax take-home pay.
Call & Put Option Calculator
Calculate option profit, loss, and breakeven at expiry for long call and put positions. See the payoff diagram for any strike and premium.
Cap Rate Calculator
Calculate the capitalisation rate (cap rate) of a real estate investment from net operating income and property value, with GRM and NOI margin.
Capital Gains Yield Calculator
Calculate capital gains yield (price appreciation) and total return including dividends for any stock, fund or asset holding.
CAPM Calculator
Calculate the expected return on an asset using CAPM: risk-free rate plus beta times the market risk premium. Plots the Security Market Line (SML).
Car Affordability Calculator
Find the maximum car price you can afford based on your income, down payment, loan terms and monthly running costs.
Car Depreciation Calculator
Calculate how much a car loses in value each year using declining-balance or straight-line depreciation, with a year-by-year value chart.
Car Lease Calculator
Calculate your monthly car lease payment from cap cost, residual value, APR and term using the standard money-factor lease formula.
车贷计算器
根据车价、首付、利率和以月计的贷款期限,算出你的月供、总利息和总成本。
Car Refinance Calculator
Calculate your new monthly car payment and total interest saved when refinancing an auto loan at a lower rate or different term.
Carried Interest Calculator
Calculate GP carried interest and LP net profit from fund returns, hurdle rate and carry percentage for private equity or venture capital funds.
Carry Trade Calculator
Calculate the net carry profit from a currency carry trade — borrow in a low-rate currency, invest in a high-rate currency, with optional leverage.
CASH Act 2020 Calculator
Estimate your proposed CASH Act 2020 stimulus payment: $2,000 per adult plus $500 per dependent, phased out by AGI and filing status.
Cash Back Calculator
Calculate annual cash back rewards from a credit card, including bonus categories and annual fees, to find your net return and break-even point.
Cash Conversion Cycle Calculator
Calculate the Cash Conversion Cycle (CCC) from DIO, DSO and DPO to measure how efficiently a business converts operations into cash flow.
Cash Flow to Debt Ratio Calculator
Calculate the cash flow to debt ratio (operating cash flow ÷ total debt) to assess how quickly a business can repay its debt from operations.
Cash Ratio Calculator
Calculate the cash ratio (cash + cash equivalents ÷ current liabilities) — the most conservative liquidity metric showing a company's ability to cover short-term obligations with only its most liquid assets.
Cash-Out Refinance Calculator
Calculate how much cash you can extract from a home refinance, the new monthly payment, and remaining equity — based on LTV, rate, and closing costs.
CD Calculator
Calculate the maturity value and interest earned on a Certificate of Deposit (CD). Enter the principal, APR, term and compounding frequency to see APY and final balance.
Cell Phone Plan Calculator
Estimate your total monthly cell phone bill: base plan, data add-ons, device payments, insurance and taxes across one or more lines.
Child Tax Credit Calculator (2024 US Federal)
Estimate your 2024 US Child Tax Credit and refundable Additional CTC (ACTC) based on number of children, AGI, and filing status.
Churn Rate Calculator
Calculate customer churn rate, retention rate, annualised churn, customer LTV, and MRR impact from a single period of lost customers.
CLTV Calculator
Calculate customer lifetime value (CLTV) from order value, purchase frequency, lifespan and gross margin, plus LTV:CAC ratio and payback period.
Cobb-Douglas Production Function Calculator
Calculate economic output Q = A × Lᵅ × Kᵝ, returns to scale, and marginal products of labor and capital.
COGS Calculator
Calculate Cost of Goods Sold using beginning inventory, purchases and ending inventory — plus gross profit and gross margin if you enter revenue.
Combined Ratio Calculator
Calculate the combined ratio for property & casualty insurance: loss ratio + expense ratio, with underwriting profit or loss.
Commercial Lease Calculator
Calculate the full cost of a commercial lease — base rent with annual escalations, NNN charges, and security deposit — over any term.
Commission Calculator
Calculate sales commission from a flat or tiered rate, add a base salary, and see total earnings and the effective commission rate.
Comparative Advantage Calculator
Identify which country or producer has the comparative advantage in each good and find the mutually beneficial terms of trade.
Compound Growth Calculator
Calculate the final value, total return, and growth multiple for any compound growth rate over years, quarters, or months.
复利计算器
看看你的钱在不同复利频率下如何通过复利增长。
Consulting Fees Calculator
Calculate consulting revenue, profit and net take-home for hourly, daily or fixed project rates — with expenses and income tax.
Consumer Surplus Calculator
Calculate consumer surplus (CS = ½ × (Pmax − P) × Q) from the demand intercept, market price and quantity. Plots the demand curve and CS triangle.
Continuous Compound Interest Calculator
Calculate final amount, interest earned and effective annual yield with continuous compounding using the formula A = Pe^(rt).
Contribution Margin Calculator
Calculate contribution margin per unit, CM ratio, break-even volume and operating profit from selling price, variable and fixed costs.
Cost of Doing Business Calculator
Calculate total operating costs, operating margin and cost-to-revenue ratio. Enter payroll, COGS, rent, marketing, insurance and other expenses against your revenue.
Cost of Equity Calculator
Calculate the cost of equity using the Capital Asset Pricing Model (CAPM): Re = Rf + β × (Rm − Rf). Shows the Security Market Line with your stock plotted on it.
Coupon Payment Calculator
Calculate periodic and annual bond coupon payments from face value and coupon rate — for annual, semi-annual, quarterly or monthly paying bonds.
Coupon Rate Calculator
Calculate a bond coupon rate from annual coupon payment and face value, plus current yield from market price — with premium/discount display.
CPA Calculator
Calculate Cost Per Acquisition (CPA) from total ad spend and conversions, plus ROAS and profit when you add total revenue.
CPC & CPM Calculator
Calculate CPC (cost per click), CPM (cost per 1,000 impressions) and CTR (click-through rate) from ad spend, impressions and clicks.
CPI Inflation Calculator
Convert money between years using actual CPI index values. Find inflation-adjusted equivalents, cumulative inflation, and purchasing power retained.
CPM Calculator
Calculate CPM (cost per 1,000 impressions), total ad cost, or total impressions for any digital advertising campaign.
Credit Card Calculator
Calculate how long it takes to pay off a credit card balance and the total interest paid at a fixed monthly payment.
Credit Card Interest Calculator
Calculate the daily, monthly and annual interest charged on a credit card balance at a given APR.
Credit Card Minimum Payment Calculator
Calculate your credit card minimum payment and see the true cost of paying only the minimum each month in total interest and years of debt.
Credit Card Payment Calculator
Calculate the fixed monthly payment needed to pay off a credit card balance in a chosen number of months at a given APR.
Credit Card Payoff Calculator
Enter your credit card balance, APR and monthly payment to see when the debt is cleared and the total interest cost.
Credit Spread Calculator
Calculate the credit spread in basis points between a corporate bond yield and a risk-free Treasury yield, plus extra income earned.
Credit Utilization Calculator
Calculate your credit utilization ratio — the percentage of available credit you are using — and see how it rates for credit-score purposes.
Cross Exchange Rate Calculator
Calculate the cross exchange rate between two currencies that share a common base — no need for a direct quote.
Cross-Price Elasticity of Demand Calculator
Calculate cross-price elasticity (XED) to determine if two goods are substitutes, complements, or independent from each other.
CTR Calculator
Calculate Click-Through Rate (CTR) from clicks and impressions. Add ad cost to get CPC and CPM alongside your CTR.
Currency Forward Rate Calculator
Calculate the fair forward exchange rate using covered interest rate parity: F = S × (1+r_d)^t / (1+r_f)^t.
Current Ratio Calculator
Calculate a company's current ratio, quick ratio and cash ratio to assess short-term liquidity and financial health.
Customer Acquisition Cost (CAC) Calculator
Calculate Customer Acquisition Cost by dividing total sales and marketing spend by the number of new customers acquired in the same period.
Customer Retention Rate Calculator
Calculate customer retention rate and churn rate from start, end, and new customer counts for any period.
Cyber Monday Calculator
Calculate your Cyber Monday final price after a percentage discount, credit-card cashback and shipping cost — see your true savings.
DART Rate Calculator
Calculate the OSHA DART rate (Days Away, Restricted or Transferred) per 100 FTE workers. Formula: (cases × 200,000) / hours worked.
Days Inventory Outstanding (DIO) Calculator
Calculate Days Inventory Outstanding (DIO) — how many days a company holds inventory before selling it — from COGS, beginning and ending inventory values.
Days Payable Outstanding Calculator (DPO)
Calculate DPO — the average days a company takes to pay suppliers — from accounts payable and cost of goods sold.
Days Sales Outstanding Calculator (DSO)
Calculate DSO — how many days on average a company takes to collect payment — from accounts receivable and net sales.
DCF Calculator
Calculate net present value (NPV) by discounting annual cash flows at your required return rate. Includes terminal value and payback period.
Deadweight Loss Calculator
Calculate the deadweight loss (efficiency loss) from a tax, price floor, price ceiling, or monopoly pricing using supply and demand elasticities.
Debt Avalanche Calculator
Calculate total interest and payoff time using the debt avalanche method — targeting the highest-APR debt first to minimise interest paid.
Debt Calculator
Calculate how long it takes to pay off a debt and the total interest you will pay, given balance, interest rate, and monthly payment.
Debt Consolidation Calculator
Compare total interest and payoff time for keeping debts separate vs consolidating into a single lower-rate loan. Includes origination fee break-even.
债务清偿计算器
了解以固定每月还款额还清信用卡或贷款余额需要多长时间,以及在此过程中你将支付的总利息。
Debt Snowball Calculator
Calculate total interest and payoff time using the debt snowball method — targeting the smallest balance first for motivating quick wins.
Debt-to-Asset Ratio Calculator
Calculate the debt-to-asset ratio — total liabilities divided by total assets — a core solvency metric showing how creditor-financed a company is.
Debt-to-Capital Ratio Calculator
Calculate the debt-to-capital ratio — total debt divided by total capital (debt + equity) — a bounded measure of a company's financial leverage.
Debt-to-Equity Ratio Calculator (D/E)
Calculate the D/E ratio — total debt divided by shareholders' equity — a fundamental financial leverage metric used in corporate analysis.
Defensive Interval Ratio Calculator (DIR)
Calculate the Defensive Interval Ratio — how many days a company can operate on its liquid assets alone without needing new revenue or financing.
Deferred Annuity Calculator
Calculate the annual payout from a deferred annuity: enter the lump-sum premium, growth rate, deferral years and payout period to see income and total return.
Deferred Payment Loan Calculator
Calculate monthly payments and total interest cost for a loan with a deferral period during which interest capitalises on the balance.
Degree of Operating Leverage (DOL) Calculator
Calculate the degree of operating leverage (DOL) from revenue, variable costs and fixed costs to measure EBIT sensitivity to sales changes.
Depreciation Calculator
Calculate annual asset depreciation using straight-line, double-declining balance, or sum of years' digits. See book value decline year by year.
Direct Material Price Variance Calculator
Calculate the direct material price variance (DMPV) to see whether actual material costs were above or below the standard budget.
折扣百分比计算器
根据原价和售价求出折扣百分比,并准确显示你节省了多少钱。
Discount Rate Calculator
Calculate the implied discount rate from present and future values, or compute WACC as the blended cost of capital for DCF valuation.
Discretionary Income Calculator
Find your discretionary income by subtracting taxes and essential living expenses from gross income — see what you can freely save or spend.
Disposable Income Calculator
Calculate disposable (take-home) income by subtracting income tax, social security, and other mandatory deductions from gross income.
Dividend Calculator
Calculate annual dividend income, dividend yield and monthly income from shares. Enter shares, dividend per share and stock price.
Dividend Discount Model Calculator (DDM)
Calculate a stock's intrinsic value using the Gordon Growth Model: P = D₁ / (r − g), with projected dividend chart.
Dividend Payout Ratio Calculator
Calculate the dividend payout ratio and retention ratio from total dividends paid and net income. Assess how much profit is returned to shareholders.
Dividend Yield Calculator
Calculate dividend yield from annual dividend per share and stock price. Compare income-generating stocks on a like-for-like basis.
Double Discount Calculator
Apply two sequential discounts to a price and find the final cost, total saving, and the equivalent single-discount rate.
Down Payment Calculator
Calculate the down payment, loan amount, closing costs and total cash needed upfront to buy a home.
Dream Come True Calculator
Find out how many months until you reach a savings goal — enter your target, current savings, monthly deposit and expected annual return.
DSCR Calculator
Calculate the Debt Service Coverage Ratio (DSCR) from net operating income and annual debt payments — used by lenders to assess loan eligibility.
DTI Calculator
Calculate your Debt-to-Income ratio (DTI) by entering monthly debt payments and gross income — see how lenders assess your borrowing capacity.
DuPont Analysis Calculator
Decompose Return on Equity into profit margin, asset turnover and financial leverage using the 3-factor and 5-factor DuPont identity.
EAR Calculator
Convert a nominal interest rate to the Effective Annual Rate (EAR) for any compounding frequency — daily, monthly, quarterly, or continuous.
Early Retirement Calculator
Calculate your FIRE number, years to financial independence, and portfolio growth curve using the safe withdrawal rate rule.
Earned Value Management Calculator
Calculate EVM project metrics: CPI, SPI, EV, CV, SV, EAC, ETC and VAC from budget, planned value, actual cost and % complete.
Earnest Money Calculator
Calculate the earnest money deposit for a home purchase, how it applies to your down payment, and your remaining cash needed at closing.
EBIT Calculator
Calculate EBIT (Earnings Before Interest and Taxes) from revenue, COGS and operating expenses — with gross margin and EBIT margin.
EBITDA Calculator
Calculate EBITDA from net income, interest, taxes, depreciation and amortization for operational profitability analysis.
EBITDA Margin Calculator
Calculate EBITDA margin (EBITDA ÷ Revenue × 100%) to benchmark operating profitability across companies and sectors.
EBT Calculator
Calculate EBT (Earnings Before Tax) from revenue, COGS, operating expenses and interest expense — and find the EBT margin.
Economic Injury Disaster Loan (EIDL) Calculator
Calculate monthly payments, total interest, and repayment schedule for an SBA Economic Injury Disaster Loan (EIDL).
Economic Profit Calculator
Calculate economic profit by subtracting both explicit costs and opportunity costs from revenue — the true measure of whether a business creates value.
Economic Value Added (EVA) Calculator
Calculate EVA — net operating profit after tax minus the capital charge — to measure whether a business creates or destroys shareholder value.
Effective Annual Yield Calculator
Calculate the Effective Annual Yield (EAY) from any holding period return — accounts for compounding to give a true like-for-like annual return.
Effective Corporate Tax Rate Calculator
Calculate a company's effective corporate tax rate — income tax expense ÷ pre-tax income — and compare it against the statutory rate.
Effective Duration Calculator
Calculate effective duration, modified duration, Macaulay duration, DV01 and convexity for a fixed-rate bond using a parallel yield shock.
Effective Interest Rate Calculator
Calculate the true effective interest rate (APR) on a loan, accounting for both the compounding of the nominal rate and any origination fee charged upfront.
ELSS Calculator
Calculate the maturity corpus and Section 80C tax savings for an ELSS investment, for both lump sum and monthly SIP modes.
Emergency Fund Calculator
Calculate your emergency fund target, current shortfall and how many months it will take to reach the goal at your monthly savings rate.
EMI Calculator
Calculate your monthly EMI, total interest and see the outstanding balance curve for any loan amount, rate and tenure.
Employee Turnover Rate Calculator
Calculate employee turnover rate and annualized retention rate from headcount and departures for any measurement period.
EMV Calculator
Calculate the Expected Monetary Value of a decision by weighting up to three scenarios by their probabilities and monetary outcomes.
Ending Inventory Calculator
Calculate ending inventory using the accounting identity Beginning + Purchases − COGS, plus inventory turnover ratio and days inventory outstanding.
Enterprise Value Calculator (EV)
Calculate enterprise value — market cap plus net debt, preferred stock, and minority interest — for M&A, company valuation, and EV/EBITDA multiples.
EOQ Calculator
Find the Economic Order Quantity (EOQ) that minimises total inventory cost — ordering cost balanced against annual holding cost.
EPF Calculator
Estimate your EPF corpus at retirement based on India's EPF contribution rules and the EPFO's 2023-24 interest rate of 8.15 % (editable).
EPS Calculator
Calculate basic and diluted Earnings Per Share (EPS) from net income, preferred dividends and share counts, plus the P/E ratio.
EPS Growth Calculator
Calculate EPS growth rate, compound annual growth rate (CAGR), P/E ratio and PEG ratio from base and current earnings per share.
Equivalent Rate Calculator
Convert a nominal interest rate from one compounding frequency to another equivalent rate — monthly to annual, quarterly to monthly, and more.
EV/EBITDA Multiple Calculator
Calculate the EV/EBITDA valuation multiple and see implied enterprise values at 5×, 8×, 10×, 12×, and 15× benchmarks.
EV/Sales Calculator
Calculate the EV/Sales (enterprise value to revenue) ratio from market cap, debt and cash — a key valuation multiple for comparing companies.
Exit Rate Calculator
Calculate investment exit returns: exit multiple (MOIC), gross and net IRR, total return, carried interest, and net proceeds to investors.
Expected Return Calculator
Calculate the probability-weighted expected return of an investment across bull, base, and bear scenarios, with standard deviation and risk metrics.
Expected Utility Calculator
Compute expected utility and certainty equivalent of a 3-scenario lottery under log, square-root, linear, or CRRA power utility functions.
Expense Ratio Calculator
Calculate how much an investment fund's annual expense ratio costs over time and compare net vs gross portfolio growth.
FFO Calculator
Calculate FFO, FFO per share, and P/FFO for REITs — the standard NAREIT metric for evaluating real estate investment trust operating performance.
FHA Loan Calculator
Calculate FHA loan monthly payments including mortgage insurance premium (MIP), total interest, and loan cost breakdown.
Fibonacci Retracement Calculator
Calculate Fibonacci retracement and extension levels (23.6%, 38.2%, 50%, 61.8%, 78.6%) from a swing high and swing low for technical analysis.
FICA Tax Calculator
Calculate 2025 FICA taxes — Social Security and Medicare — for employees and self-employed individuals, including the Additional Medicare Tax.
FIFO Inventory Calculator
Calculate cost of goods sold (COGS) and ending inventory value using the FIFO (First In, First Out) inventory costing method across up to three purchase lots.
Finance Charge Calculator
Calculate the finance charge on a credit card or revolving loan balance using APR, billing period, and the Average Daily Balance or daily/monthly periodic rate method.
Financial Leverage Ratio Calculator
Calculate financial leverage ratios: debt-to-equity, debt-to-assets, equity multiplier, interest coverage, and degree of financial leverage (DFL).
芬兰薪资计算器2026
2026年芬兰税后薪资计算器:累进制国家税、市政税、教会税、TyEL养老金及失业保险——精确查看实际到手收入。
FIRE Calculator
Calculate your FIRE number, years to financial independence, and portfolio growth using the 4 % safe withdrawal rule and compound returns.
Fisher Effect Calculator
Solve the Fisher Effect equation for the nominal rate, real rate or expected inflation — with the exact and approximate forms side by side.
Fisher Equation Calculator
Calculate the real interest rate from the nominal rate and expected inflation using the exact Fisher equation r = (1+i)/(1+π) − 1.
Fixed Asset Turnover Ratio Calculator
Calculate the fixed asset turnover ratio (FATO) from net revenue and net fixed assets to measure how efficiently a company uses PP&E.
Fixed Deposit (FD) Calculator
Calculate FD maturity amount and interest for any compounding frequency with optional TDS/withholding tax deduction.
Florida Overtime Calculator
Calculate Florida overtime pay: regular + 1.5× for hours over 40 per week under federal FLSA rules applicable in Florida.
Forward Premium Calculator
Calculate the annualised forward premium or discount between a spot and forward exchange rate for any contract period.
Forward Rate Calculator
Calculate the implied forward interest rate between two maturities from their spot rates using the no-arbitrage bootstrapping formula.
Free Cash Flow Calculator
Calculate free cash flow (FCF) from operating cash flow minus CapEx, plus FCF margin, FCF yield and conversion rate.
Free Cash Flow to Equity (FCFE) Calculator
Calculate FCFE — the cash available to equity shareholders — from net income, D&A, CapEx, working capital changes and net borrowings.
Free Cash Flow to Firm (FCFF) Calculator
Calculate FCFF (unlevered free cash flow to the firm) from EBIT, tax rate, D&A, CapEx and working capital change — the input to enterprise-value DCF models.
Free Float Calculator
Calculate a stock's free float percentage and shares, the portion publicly tradeable after excluding promoter, government and locked-in holdings.
Full-Time Equivalent (FTE) Calculator
Calculate total FTE from full-time and part-time employees. Converts part-time hours to FTE units for headcount planning and workforce reporting.
Future Salary Calculator
Project your salary over time with annual raises and inflation — see both nominal and real (purchasing-power) values year by year.
终值计算器
运用货币时间价值计算资金的终值。按任意利率、期限和复利频率,预测一笔本金加上定期追加投入在复利增长下的结果。
Futures Contract Calculator
Calculate futures contract P&L, notional value, initial margin required and leverage from entry price, exit price and contract size.
GDP Calculator
Calculate GDP using the expenditure approach: GDP = C + I + G + (X − M). See each component's share of total output.
GDP Deflator Calculator
Calculate the GDP deflator from nominal and real GDP, and the implied inflation rate between two periods.
GDP Gap Calculator
Calculate the GDP output gap (actual minus potential GDP) as a percentage, and identify recessionary or inflationary gaps.
GDP Growth Rate Calculator
Calculate GDP growth rate between two periods — simple growth, compound annual growth rate (CAGR), and annualised quarterly or monthly rates.
GDP Per Capita Calculator
Calculate GDP per capita (GDP divided by population) to compare living standards across countries or time periods.
Georgia Overtime Calculator
Calculate Georgia overtime pay for hours over 40 per week. Georgia follows federal FLSA: overtime is 1.5× the regular rate. 2025 federal minimum wage: $7.25/hr.
Gift of Equity Calculator
Calculate the gift of equity when a family member sells property below market value. Find the effective down payment, LTV and estimated mortgage payment.
Gini Coefficient Calculator
Calculate the Gini coefficient from five income quintiles and visualise the Lorenz curve vs perfect equality.
GMROI Calculator
Calculate GMROI to measure how many dollars of gross margin your business earns for every dollar invested in average inventory.
Gold Melt Value Calculator
Calculate the melt value of gold jewelry, coins or bars from weight, karat purity and the current spot price per troy ounce.
Goodwill Calculator
Calculate accounting goodwill (or bargain purchase gain) for a business acquisition: purchase price minus net fair value of identifiable assets.
Google AdSense Calculator
Estimate monthly and annual Google AdSense revenue from your pageviews, click-through rate and cost per click.
Graham Number Calculator
Calculate Benjamin Graham's intrinsic value formula: √(22.5 × EPS × BVPS) to find a stock's maximum fair price.
Gratuity Calculator
Calculate your India gratuity payout under the Payment of Gratuity Act 1972 — basic salary, years served, and coverage type.
Gross Margin Calculator
Calculate gross profit and gross margin percentage from revenue and cost of goods sold (COGS), plus the markup on COGS.
Gross Rent Multiplier Calculator
Calculate the Gross Rent Multiplier (GRM) and gross yield for a rental property from the purchase price and monthly rent.
Gross to Net Calculator
Convert gross salary to net take-home pay by applying income tax, social security and other deduction rates — monthly or annual.
Growing Annuity Calculator
Calculate the present value and future value of a growing annuity — a series of cash flows that increase at a constant rate each period.
GRP Calculator
Calculate GRP (Gross Rating Points), Cost Per Point (CPP) and Cost Per Thousand (CPM) for any advertising campaign. Enter reach, frequency and spend to plan media budgets.
GST + QST Calculator
Calculate Canadian GST (5%) and Quebec QST (9.975%) — add both taxes to a pre-tax price or back them out of a tax-inclusive total.
GTIN Check Digit Calculator
Calculate or validate the GS1 check digit for GTIN-8, GTIN-12 (UPC-A), GTIN-13 (EAN-13) and GTIN-14 barcodes.
HEALS Act Stimulus Check Calculator
Estimate your stimulus check under the 2020 HEALS Act proposal: $1,200/adult + $500/child, phasing out from $75,000 AGI.
HEALS Act Unemployment Benefit Calculator
Estimate two-phase enhanced unemployment benefits modelled on the 2020 US HEALS Act: state UI plus a federal supplement, then a wage-replacement target.
HEALS vs HEROES Act Stimulus Comparison Calculator
Compare your estimated stimulus payment under the 2020 Senate HEALS Act ($500/dependent) versus the House HEROES Act ($1,200/dependent) — both never enacted.
Hedge Ratio Calculator
Calculate the minimum-variance hedge ratio h* = ρ × (σS/σF) and the number of futures contracts needed to optimally hedge a spot market exposure.
HELOC Calculator
Calculate HELOC interest-only draw-period payments, fully amortised repayment payments, and total interest cost.
HEROES Act Stimulus Calculator
Estimate what you would have received under the House HEROES Act (H.R.6800) — $1,200/adult and $1,200/dependent, up to 3 dependents, with income phase-out.
HHI Calculator
Calculate the Herfindahl-Hirschman Index (HHI) to measure market concentration — enter up to 10 firm market shares to get the index and DOJ classification.
High-Low Method Calculator
Separate fixed and variable costs from two data points using the high-low method of cost accounting.
Holding Period Return Calculator
Calculate the holding period return (HPR) of any investment: enter beginning value, ending value, and any income received to get the total and annualized return.
Home Affordability Calculator
Find the maximum home price you can afford using the 28/36 debt-to-income rule, your down payment and current mortgage rates.
Home Improvement Loan Calculator
Calculate monthly payments, total interest and total cost for a home improvement or renovation loan from the loan amount, rate and term.
Home Loan Calculator
Calculate your monthly home loan payment, total interest and see how your loan balance falls over time from home price, down payment, rate and term.
Home Mortgage Calculator
Calculate your complete monthly mortgage payment including principal, interest, property tax, homeowner insurance and PMI (PITI).
Home Value Estimator (US)
Estimate your US home's current market value using purchase price, annual appreciation, and capital improvements.
Hourly to Annual Salary Calculator
Convert an hourly wage to annual, monthly, bi-weekly and weekly gross salary instantly — adjust hours per week and weeks worked.
Hourly to Salary Calculator
Convert your hourly pay rate to daily, weekly, bi-weekly, semi-monthly, monthly and annual salary equivalents.
Hourly to Salary with Overtime Calculator
Calculate annual salary from an hourly rate including overtime pay — enter regular hours, overtime hours and the overtime multiplier.
Hourly Wage Calculator
Convert any salary (annual, monthly, bi-weekly or weekly) to an equivalent hourly wage based on your hours worked per week.
Hours Pay Calculator
Calculate your total pay from hours worked at an hourly rate — including overtime with a custom multiplier (time-and-a-half, double time).
HR Software ROI Calculator
Calculate the return on investment from HR software: labour savings vs implementation and subscription costs, payback period, and net benefit.
HRA Exemption Calculator
Calculate your annual HRA exemption under Indian Income Tax Section 10(13A): lowest of actual HRA, % of basic, and rent minus 10% of basic.
Illinois Overtime Calculator
Calculate Illinois weekly gross pay with overtime: regular hours at your rate, every hour over 40 paid at 1.5× under FLSA.
Illinois Tax Calculator
Estimate Illinois income tax (4.95% flat), federal income tax (2025 brackets), Social Security and Medicare for any filing status.
Immediate Annuity Calculator
Calculate the periodic payment from a fixed-term immediate annuity: enter a lump sum, interest rate and term to find monthly, quarterly or annual income.
Income Elasticity of Demand Calculator
Calculate income elasticity of demand (IED) to classify goods as luxury, normal, necessity, or inferior based on how demand reacts to income changes.
通货膨胀计算器
看看通货膨胀如何抬高未来的金钱成本,并在若干年内侵蚀一笔金额的购买力。
Information Ratio Calculator
Calculate the information ratio: risk-adjusted active return of a portfolio vs its benchmark. Enter portfolio return, benchmark return and tracking error.
Interest Coverage Ratio Calculator
Calculate the interest coverage ratio (ICR) from EBIT and interest expense — assess a company's ability to service its debt.
Interest Rate Calculator
Solve for the annual interest rate given a starting amount, final value and time period — simple or compound interest.
Interest Rate Parity Calculator
Calculate the theoretical forward exchange rate using covered interest rate parity (IRP), given spot rate and both countries' interest rates.
只付利息房贷计算器(Realkredit)
计算含只付利息期的房贷还款 — 期间及期后月供、总费用和剩余债务曲线。支持丹麦realkredit管理费率(bidrag)。
Internal Rate of Return (IRR) Calculator
Calculate the IRR of an investment from its initial cost and annual cash inflows — solved numerically via bisection.
Intrinsic Value Calculator
Calculate the intrinsic value of a stock using the Benjamin Graham revised formula and the Graham Number — with margin of safety.
Inventory Turnover Calculator
Calculate inventory turnover ratio and days inventory outstanding (DIO) from COGS and beginning/ending inventory.
Investment Calculator
Project the final value of an investment with an initial lump sum, regular contributions, and compound interest over any period.
Investment Fees Calculator
See exactly how annual fund fees (expense ratios) erode your investment returns and compound into a large long-term cost.
IRA Calculator
Project IRA balance growth to retirement, compare Traditional (pre-tax) vs Roth (post-tax) after-tax values, based on 2025 contribution limits.
Jensen's Alpha Calculator
Calculate Jensen's alpha to measure how much a portfolio outperformed or underperformed its CAPM-expected return for the level of systematic risk taken.
Jumbo Loan Calculator
Calculate monthly payments, total interest, and total cost for a jumbo mortgage (loan above the 2025 FHFA conforming limit of $806,500).
Labor Cost Calculator
Calculate the true annual cost of an employee: gross wages plus employer payroll taxes, benefits and overhead burden.
Labor Force Participation Rate Calculator
Calculate the labor force participation rate (LFPR) from employed, unemployed, and not-in-labor-force population counts.
Land Loan Payment Calculator
Calculate monthly payments, total interest, and total cost for a raw land loan with down payment, rate, and term.
LCR Calculator
Calculate the Liquidity Coverage Ratio (LCR) per Basel III: HQLA divided by 30-day net cash outflows, with inflow cap applied.
Lease Mileage Calculator
Estimate your car lease over-mileage cost at lease end and compare whether buying extra miles upfront saves money.
Lemonade Stand Calculator
Calculate daily profit, profit margin, and break-even point for a lemonade stand. Great for kids, classroom projects, and small business basics.
Lerner Index Calculator
Calculate the Lerner Index (P − MC) / P to measure a firm's market power — from 0 (perfect competition) to 1 (pure monopoly).
Levered Free Cash Flow Calculator
Calculate Levered Free Cash Flow (LFCF) from net income, D&A, CapEx, working capital changes and debt repayment — with LFCF margin.
LGD Calculator
Calculate Loss Given Default (LGD), recovered amount, and Expected Loss (EL) from EAD, recovery rate and probability of default.
Lifetime Earnings Calculator
Calculate total gross and after-tax earnings over your entire career, including annual salary raises and bonuses, from start age to retirement.
LIFO Inventory Calculator
Calculate COGS and ending inventory value using the LIFO (Last-In, First-Out) method for up to three purchase lots, with a FIFO comparison.
Liquid Net Worth Calculator
Calculate your liquid net worth — only the assets you can convert to cash within days, minus short-term liabilities.
Loan Balance Calculator
Find the remaining loan balance at any point during a mortgage or loan — enter the original amount, rate, term, and payments made.
Loan Calculator
Calculate your monthly loan payment, total interest, total cost of credit and APR for any loan amount, rate, term and upfront fee.
Loan Comparison Calculator
Compare two loans side by side: see which has the lower monthly payment, less total interest, and a lower overall cost.
贷款 EMI 计算器
为任意贷款金额、利率和期限计算你的每月贷款 EMI、总利息和总还款额。
Loan Interest Calculator
Calculate total interest paid on a loan over its full term — enter the amount, annual rate, and term in months.
Loan Payment Calculator
Calculate monthly, bi-weekly, or weekly loan payments from the amount, annual rate, and term — and see total interest and overall cost.
Loan Repayment Calculator
Calculate your monthly loan repayment, total interest paid and principal-vs-interest breakdown for any fixed-rate loan.
Loan Tenure Calculator
Calculate how many months (tenure) it takes to repay a loan given the principal, annual interest rate, and monthly EMI.
Loan-to-Value (LTV) Calculator
Calculate the LTV ratio for a mortgage or home loan, your equity percentage, and whether PMI is likely required.
Long-Term Care Cost Calculator
Estimate the total cost of long-term care — home aide, assisted living or nursing home — with annual inflation and a funding-gap analysis.
Loss Ratio Calculator
Calculate the loss ratio, combined ratio and underwriting profit for an insurance portfolio from incurred losses and earned premium.
Lost Wages Assistance Calculator
Estimate total lost wages from injury, illness or disability, factoring in any wage-replacement benefits from insurance or workers' compensation.
Lottery Annuity Calculator
Compare a lottery annuity payout to its lump-sum cash value and see what you keep after tax — with year-by-year receipts.
Lottery Tax Calculator
Calculate how much of a lottery jackpot you keep after federal and state income tax, for lump sum or annuity payouts.
Lump Sum + SIP Calculator
Calculate the total future corpus from a combined one-time lump sum investment and monthly SIP at a given annual return rate.
Lump Sum Calculator
Calculate the future value and total returns of a one-time lump sum investment at a given annual return rate over any investment period.
MAGI Calculator
Calculate your 2024 MAGI for Roth IRA contributions and traditional IRA deductibility — enter AGI plus common add-backs.
Man-Hours Calculator
Calculate total man-hours, man-days and estimated labour cost for a project from workers, hours per day and duration.
Margin 2 Sets Calculator
Calculate individual and blended gross margins for two product sets or business segments, showing how the product mix affects overall profitability.
Margin After Discount Calculator
Calculate how a percentage discount erodes your gross margin — see the new margin, profit per unit and how much margin the discount costs.
Margin and VAT Calculator
Calculate the net selling price, VAT amount, and VAT-inclusive gross price from a cost price, target gross margin, and VAT rate.
Margin Calculator
Calculate gross profit margin and markup from revenue and cost. Margin = (Revenue − Cost) ÷ Revenue × 100%.
Margin Call Calculator
Calculate the exact share price that triggers a margin call based on your initial and maintenance margin requirements.
Margin Interest Calculator
Calculate the daily, monthly and total interest on a margin loan for any holding period at your broker's annual margin rate.
Margin of Safety Calculator
Calculate the investing margin of safety (discount to intrinsic value) and the accounting margin of safety (sales cushion above break-even).
Marginal Cost Calculator
Calculate marginal cost — the extra cost of producing one more unit — from two total cost and output quantity observations.
Marginal Revenue Calculator
Calculate marginal revenue — the additional revenue from selling one more unit — from two total revenue and output quantity observations.
Markdown Calculator
Calculate the markdown percentage from original and sale prices, or find the sale price from a markdown percentage.
Market Capitalization Calculator
Calculate a company's market cap, enterprise value and P/E ratio from share price, shares outstanding, debt, cash and EPS.
Marketing Conversion Rate Calculator
Calculate conversion rate, cost per acquisition, revenue, ROI and ROAS from visitors, conversions, spend and average order value.
加价计算器
根据产品成本和加价百分比计算售价,以及单位利润和由此产生的利润率。
Maturity Value Calculator
Calculate the maturity value of an investment or loan using simple or annually compounded interest — principal, rate and term in one step.
Maximum Drawdown Calculator
Calculate the maximum drawdown (MDD) from peak to trough and the gain needed to fully recover — the standard portfolio risk metric.
Mega Millions Payout Calculator
Calculate your Mega Millions take-home payout for the lump-sum cash option and 30-year annuity after federal and state taxes.
Mileage Reimbursement Calculator
Calculate mileage reimbursement for business travel using the IRS standard rate or a custom rate, with weekly and annual projections.
Millionaire Calculator
Calculate how many years it takes to reach a savings target given monthly contributions, annual return rate, and starting balance.
Modified IRR Calculator (MIRR)
Calculate Modified Internal Rate of Return (MIRR) using separate reinvestment and finance rates — a more realistic alternative to plain IRR.
Money Counter
Count the total value of US bills and coins by entering the quantity of each denomination — instant total with a breakdown.
Money Factor Calculator
Convert money factor to APR and calculate monthly auto lease payments: depreciation + finance charge breakdown.
Money Market Account Calculator
Calculate the future balance and interest earned on a money market account with optional monthly deposits and compound interest.
Money Multiplier Calculator
Calculate the money multiplier and total deposits created from an initial injection using the fractional reserve formula.
Money Per Hour Calculator
Convert any salary (annual, monthly, weekly or daily) to an hourly rate based on your actual working hours.
Money Supply Calculator
Calculate the theoretical broad money supply from a monetary base and reserve requirement ratio using the money multiplier model.
Month-Over-Month Calculator
Calculate the month-over-month (MoM) growth rate, absolute change, and annualized equivalent for any metric.
Monthly Income Calculator
Convert hourly, daily, weekly, fortnightly, quarterly or annual income into your gross monthly equivalent with a full pay-period breakdown.
Monthly Income from Hourly Rate Calculator
Calculate your gross monthly income from an hourly wage — enter your rate, hours per day, days per week and weeks per year.
Moratorium EMI Calculator
Calculate how a loan moratorium (payment holiday) changes your EMI or tenure — see the new monthly payment and total extra interest cost.
Mortgage Acceleration Calculator
See how much interest you save and how many years you cut off your mortgage by making extra monthly principal payments.
Mortgage Amortization Calculator
Generate a complete year-by-year mortgage amortization schedule showing principal paid, interest paid, remaining balance, and equity percentage.
房贷计算器
根据贷款金额、年利率和以年计的贷款期限,算出你的每月房贷还款额、总利息和总成本。
Mortgage Calculator with Taxes and Insurance
Calculate your total monthly PITI mortgage payment — principal, interest, property taxes, homeowners insurance and PMI — in one place.
Mortgage Comparison Calculator
Compare two mortgage scenarios side by side: monthly payments, total interest and lifetime cost — so you can pick the better deal.
Mortgage Extra Payments Calculator
See how adding extra monthly payments to your mortgage cuts total interest and shortens the loan term — with side-by-side comparison.
Mortgage Payoff Calculator
Enter your remaining mortgage balance, interest rate and monthly payment to find out exactly when your mortgage will be paid off and the total interest left to pay.
Mortgage Points Calculator
Calculate the break-even point and lifetime saving from buying mortgage discount points to lower your interest rate.
Mortgage Prepayment Calculator
Calculate how a one-time lump-sum prepayment reduces your mortgage term or monthly payment — and how much interest it saves you.
Mortgage Prepayment Penalty Calculator
Estimate the prepayment penalty for breaking or paying off your mortgage early — using the Interest Rate Differential (IRD) or 3-months interest method.
Mortgage Rate Calculator
Calculate your fixed-rate mortgage monthly payment, total interest paid and full repayment cost from loan amount, rate and term.
Mortgage Refinance Calculator
Compare your current mortgage with a refinance offer — calculate monthly savings, break-even months and net lifetime interest savings after closing costs.
Moving Average Calculator
Calculate Simple Moving Average (SMA) and Exponential Moving Average (EMA) for any data series — prices, sales, signals or measurements.
MPC Calculator
Calculate the Marginal Propensity to Consume (MPC), Marginal Propensity to Save (MPS), and the Keynesian fiscal multiplier from income and spending changes.
MPS Calculator
Calculate the Marginal Propensity to Save (MPS), MPC, and the Keynesian fiscal multiplier from income and savings changes across two periods.
Mutual Fund Calculator
Estimate your mutual fund corpus from a lump sum investment, monthly SIP, expected annual return, and investment period — with a full breakdown of invested vs earned.
MVA Calculator
Calculate Market Value Added (MVA) — the difference between a firm's market capitalisation and book equity — to measure wealth created for shareholders.
Natural Rate of Unemployment Calculator (NAIRU)
Calculate cyclical unemployment and the GDP output gap using Okun's law, given the actual unemployment rate and the NAIRU.
NAV Calculator
Calculate Net Asset Value (NAV) per share for mutual funds, ETFs, or investment companies, plus the premium or discount to market price.
Net Debt Calculator
Calculate net debt (total debt minus cash and equivalents) and key leverage ratios — Net Debt/EBITDA and net gearing — for corporate financial analysis.
Net Effective Rent Calculator
Calculate net effective rent (NER) by blending free rent months and tenant improvement allowances into a single monthly figure — the true economic cost of a lease.
Net Income Calculator
Calculate net income from revenue, COGS, operating expenses, interest and tax rate — the full income statement in one step.
Net Operating Assets (NOA) Calculator
Calculate Net Operating Assets — the capital deployed in core business operations — from balance-sheet totals by stripping out financial items.
Net Operating Income (NOI) Calculator
Calculate NOI from gross rental income, vacancy rate and operating expenses. Includes cap rate and gross rent multiplier for property valuation.
Net Operating Working Capital (NOWC) Calculator
Calculate NOWC — the operating current assets minus operating current liabilities — to measure the short-term capital tied up in core business operations.
Net Present Value (NPV) Calculator
Calculate NPV of a project with uniform annual cash flows. Shows profitability index, payback period and an NPV-vs-discount-rate sensitivity curve.
Net Profit Margin Calculator
Calculate net profit margin as a percentage of revenue — see how much of every dollar of sales becomes actual profit.
净薪资计算器
计算扣税后的净薪资,支持瑞典、芬兰、丹麦和挪威预设 — 市政税、国家税、社会保险费和税收抵免,均可编辑。
Net to Gross Calculator
Convert a net (take-home) amount back to the gross figure — useful for salary, freelance rates, tax, VAT and price calculations.
Net Worth Calculator
Calculate your personal net worth by subtracting total liabilities from total assets — cash, investments, property, loans and debts.
New York Overtime Calculator
Calculate New York overtime pay: hours over 40 per workweek are paid at 1.5× (time and a half) the regular rate under federal FLSA.
New York Tax Calculator
Estimate your 2024 New York state income tax, NYC local tax, and federal income tax from your annual gross income.
NOPAT Calculator
Calculate NOPAT from EBIT and the effective tax rate, with optional ROIC if you supply invested capital.
NPS Calculator
Estimate your NPS Tier I corpus, annuity amount and monthly pension at retirement based on salary, contribution rates and expected returns.
Calculate the Net Promoter Score (NPS) from Promoter, Passive, and Detractor counts with a segment breakdown.
NSFR Calculator
Calculate the Net Stable Funding Ratio (NSFR) for Basel III compliance — check whether Available Stable Funding meets Required Stable Funding.
Occupancy Rate Calculator
Calculate occupancy rate, vacancy rate, and RevPAR for hotels, short-term rentals, or any capacity-based business.
Off-Day Calculator
Calculate working days, weekend days, and total off days in any calendar period for payroll, project planning, or financial accruals.
Okun's Law Calculator
Solve Okun's law for GDP growth, unemployment change, or the Okun coefficient — the empirical link between economic output and joblessness.
Online Marketing ROI Calculator
Calculate marketing ROI, ROAS, cost per acquisition and CLV/CPA ratio for any digital marketing campaign.
Operating Asset Turnover Calculator
Calculate operating asset turnover — revenue divided by operating assets — to measure how efficiently a business uses its working assets.
Operating Cash Flow Calculator (Indirect Method)
Calculate operating cash flow (OCF) from net income, depreciation, and changes in working capital using the indirect method.
Operating Cash Flow Ratio Calculator
Calculate the operating cash flow ratio (OCF ÷ current liabilities) to assess a company's short-term liquidity from actual cash generation.
Operating Margin Calculator
Calculate operating margin (EBIT margin) from revenue, cost of goods sold and operating expenses — a key profitability metric for any business.
Opportunity Cost Calculator
Calculate the opportunity cost of choosing one investment or spending path over the best available alternative using compound growth.
Optimal Hedge Ratio Calculator
Calculate the minimum-variance hedge ratio h* = ρ × (σ_S / σ_F), hedge effectiveness R², and number of futures contracts needed to hedge a position.
Optimal Price Calculator
Find the profit-maximising price using the Lerner pricing rule: P* = MC × |ε| / (|ε| − 1), given marginal cost and price elasticity of demand.
Options Spread Calculator
Calculate max profit, max loss, breakeven, and return-on-risk for bull call, bear put, bull put, and bear call vertical option spreads.
Overtime Calculator
Calculate overtime pay for any overtime threshold and multiplier — see regular pay, overtime pay and total gross earnings.
Overtime Paycheck Calculator
Calculate your paycheck with overtime: gross pay, estimated tax withheld and net take-home pay for any pay period.
Pag-IBIG Housing Loan Calculator
Calculate monthly amortisation, total interest and payment schedule for a Philippine Pag-IBIG (HDMF) housing loan.
Pakistan Income Tax Calculator
Estimate Pakistani salaried income tax for Tax Year 2025 (FY 2024-25) using the Finance Act 2024 slab rates from the FBR.
Parking Ratio Calculator
Calculate parking ratio (spaces per 1,000 sq ft of GLA) for office, retail, restaurant and other building types against industry benchmarks.
Partially Amortized Loan Calculator
Calculate monthly payments and the balloon payment for a partially amortized loan — payments based on a long amortization period with a lump sum due sooner.
Pay Raise Calculator
Calculate your new salary after a percentage or flat pay raise. See the annual, monthly and hourly figures, plus the extra monthly income.
Payback Period Calculator
Calculate the simple and discounted payback period for any investment. Enter initial cost and net cash flows to see when you break even.
Payday Loan Calculator
Calculate the total repayment, finance charge and true APR of a payday loan — enter loan amount, fee and term in days.
PayPal Fee Calculator
Calculate PayPal fees on a transaction and find how much to charge to receive a specific amount after fees — 2024 US rates, editable.
PEG Ratio Calculator
Calculate the PEG ratio from the P/E ratio and expected EPS growth rate to see whether a stock is fairly valued relative to its growth.
Pence to Pounds Calculator
Convert any number of pence to pounds instantly. Shows whole pounds, remaining pence, and the decimal pound value.
Percent Off Calculator
Calculate the sale price and total savings when a percentage discount is applied to an original price.
Percentage Return Calculator
Calculate the percentage return on any investment, plus the absolute gain and the annualised CAGR over your chosen holding period.
Perpetuity Calculator
Calculate the present value of a flat or growing perpetuity using PV = C/r or the Gordon Growth Model PV = C/(r − g).
Personal Loan Calculator
Calculate your personal loan monthly payment, total interest and repayment schedule. Supports monthly, bi-weekly and weekly payments.
Philippines Income Tax Calculator
Estimate Philippine income tax for compensation earners under the TRAIN Law (RA 10963) graduated rates effective from 2023. See monthly and annual tax and take-home pay.
Phillips Curve Calculator
Calculate the implied inflation rate from the expectations-augmented Phillips Curve (Friedman–Phelps): π = π* − β(u − u*). Plots the trade-off curve.
PITI Calculator
Calculate your full monthly mortgage payment (PITI): Principal, Interest, property Taxes and homeowners Insurance — plus PMI if applicable.
Pivot Point Calculator
Calculate intraday pivot points and support/resistance levels (S1–S3, R1–R3) from the prior session high, low and close.
PMI Calculator
Calculate monthly and annual PMI, your loan-to-value ratio, and when PMI will drop off your mortgage.
Portfolio Beta Calculator
Calculate portfolio beta as the weighted average of individual asset betas — enter up to 6 holdings with their allocation weights.
Post Office Monthly Income Scheme (MIS) Calculator
Calculate monthly interest payouts, total interest earned and effective yield for India's Post Office Monthly Income Scheme (MIS). Rate 7.4% p.a. (Q1 FY2024-25, editable).
Post-Judgment Interest Calculator
Calculate accrued interest on an unpaid court judgment from the award date to payment date using your jurisdiction's statutory annual rate.
Powerball Calculator
Calculate the expected value of a Powerball ticket and your probability of winning the jackpot, after tax and cash-option discount.
PPF Calculator
Calculate PPF maturity value, total interest earned and corpus growth year by year for any deposit amount, rate and period.
PPP Calculator
Calculate the PPP-implied exchange rate between two currencies from basket prices and compare it to the actual market rate to reveal over/under-valuation.
PPP Loan Calculator
Estimate your PPP loan amount and forgiveness under CARES Act rules. Calculates 2.5× or 3.5× monthly payroll, forgiveness eligibility, and any unforgiven balance.
Pre-Money and Post-Money Valuation Calculator
Calculate post-money valuation, investor equity %, and implied share price from a startup funding round.
Present Value Calculator
Calculate the present value (PV) of a future lump sum using a discount rate and compounding frequency — essential for DCF analysis and investment decisions.
Price × Quantity Calculator
Calculate the total cost from unit price and quantity, with optional percentage discount and tax/VAT applied in the correct commercial order.
Price Elasticity of Demand Calculator
Calculate the price elasticity of demand (PED) from two price–quantity pairs and classify demand as elastic, inelastic or unit elastic.
Price Elasticity of Supply Calculator
Calculate the price elasticity of supply (PES) from two price–quantity pairs and classify supply as elastic, inelastic or unit elastic.
Price Per Share Calculator
Calculate the true cost per share including brokerage fees. Find your average cost basis to know exactly when a position becomes profitable.
Price Per Square Foot Calculator
Calculate price per square foot for any property. Compare homes, apartments or commercial spaces on the same metric regardless of size.
Price Per Square Meter Calculator
Calculate price per m² (and per ft²) from a total property price and floor area — compare real estate values at a glance.
Price-to-Book Ratio Calculator (P/B)
Calculate the P/B ratio from stock price and book value per share to assess whether a stock trades below or above its net asset value.
Price-to-Cash-Flow Ratio Calculator (P/CF)
Calculate the P/CF ratio from stock price and operating cash flow per share — a harder-to-manipulate valuation metric than P/E.
Price-to-Earnings Calculator (P/E Ratio)
Calculate the P/E ratio and earnings yield from stock price and EPS — the most widely used equity valuation metric, explained.
Price-to-Sales Ratio Calculator (P/S Ratio)
Calculate the P/S ratio from stock price and revenue per share, with instant valuation zone context for any sector.
Private Savings Calculator
Calculate private savings (disposable income minus consumption), private savings rate, and optionally public and national savings from income, taxes, and spending.
Productivity Calculator
Calculate labor productivity in units per man-hour, output per worker, and output per day from headcount, hours, and total output.
Profit Calculator
Calculate gross profit, net profit, profit margin and markup from revenue, cost of goods sold, and operating expenses.
Profitability Index Calculator
Calculate the Profitability Index (PI) and Net Present Value (NPV) for equal annual cash flows. PI > 1 signals a value-creating project.
Prorated Rent Calculator
Calculate the prorated rent for a partial month when you move in or out mid-month. Supports both actual-day and 30-day lease basis calculations.
Prorated Salary Calculator
Calculate the prorated salary for a partial pay period — for new hires starting mid-month, leavers, or any partial pay period. Covers monthly, bi-weekly and weekly payroll.
Put-Call Parity Calculator
Calculate the implied put or call price using the put-call parity equation, or check whether two option prices are arbitrage-free.
PVGO Calculator
Calculate PVGO (Present Value of Growth Opportunities) to split a stock price into its no-growth earnings value and the market premium placed on future growth.
PVIFA Calculator
Calculate the PVIFA factor and the present value of an ordinary annuity from a periodic interest rate, years, and payment amount.
Quick Ratio Calculator
Calculate the quick ratio (acid-test ratio) to assess a company's short-term liquidity using cash, securities and receivables.
Rate of Pay Calculator
Convert hourly pay to annual, monthly, biweekly, weekly, and daily rates. Enter your hourly wage, hours per week, and weeks per year.
Rate of Return Calculator
Calculate total return percentage and compound annual growth rate (CAGR) from an initial investment value, final value, and holding period.
RD Calculator
Calculate the maturity value and interest earned on a Recurring Deposit (RD). Enter your monthly installment, interest rate and term to see the total payout.
Real Estate Commission & VAT Calculator
Calculate real estate agent commission, VAT on that commission, and net seller proceeds from a property sale.
Real Estate Commission Calculator
Calculate the total real estate agent commission, each agent's share, and the seller's net proceeds from a property sale.
Real GDP Calculator
Convert nominal GDP to real GDP using the GDP deflator and calculate the real economic growth rate between two years.
Real Interest Rate Calculator
Calculate the real interest rate from a nominal rate and inflation using the exact Fisher equation and the simpler approximation.
Real Rate of Return Calculator
Calculate the inflation-adjusted, after-tax real rate of return on an investment and see the true growth in purchasing power over time.
Receivables Turnover Calculator
Calculate the accounts receivable turnover ratio and Days Sales Outstanding (DSO) to measure how efficiently a business collects credit sales.
Refinance Calculator
Calculate monthly payment savings, break-even months and net lifetime interest savings when refinancing any loan — auto, personal, student or home equity.
Remote vs On-Site Workers Cost Calculator
Compare the true annual cost of a remote workforce versus on-site employees — salary, office space, equipment, stipends and overhead.
Rent Calculator
Calculate your rent-to-income ratio, total housing cost and monthly surplus. See whether your rent passes the 30% rule and how it fits into your overall budget.
Rent Increase Calculator
Calculate your new monthly rent after a percentage or flat-amount increase, plus the annual impact.
Rent or Buy Calculator
Compare the total net cost of renting vs buying a home over your chosen time horizon, accounting for mortgage, equity, and investment returns.
Rental Commission Calculator
Calculate the real estate agent commission on a rental property — as a percentage of annual, total, or monthly rent.
Rental Property Calculator
Analyse a rental property investment: monthly cash flow, cap rate, cash-on-cash return, NOI and gross rent multiplier.
Reserve Ratio Calculator
Calculate required reserves, loanable funds and the money multiplier from bank deposits and the reserve requirement ratio.
Residual Income Calculator
Calculate residual income (RI) — the profit left after subtracting the equity charge — to assess whether a business creates or destroys economic value.
Retained Earnings Calculator
Calculate ending retained earnings using the formula: Beginning RE + Net Income − Dividends Paid, with the retention ratio.
Retention Ratio Calculator
Calculate the retention (plowback) ratio — the share of net income reinvested rather than paid as dividends.
退休储蓄计算器
根据你的当前年龄、退休年龄、当前储蓄、每月供款和预期年回报率,预测你的退休储备金。
Retirement Withdrawal Calculator
Calculate sustainable retirement withdrawals, portfolio longevity, and the year-by-year balance using real returns and inflation-adjusted withdrawals.
Return on Capital Employed (ROCE) Calculator
Calculate ROCE — EBIT divided by capital employed — to measure how efficiently a company uses its long-term capital to generate profit.
Revenue Calculator
Calculate total revenue, gross profit, operating profit and margins from unit price, units sold, COGS and operating expenses.
Revenue Growth Calculator
Calculate revenue growth rate between two periods and CAGR across multiple years from previous and current revenue figures.
Revenue Per Employee Calculator
Calculate revenue per employee — divide annual revenue by headcount to measure workforce productivity and benchmark against industry peers.
RMD Calculator
Calculate your IRS Required Minimum Distribution (RMD) from a traditional IRA or 401(k) using the 2022 Uniform Lifetime Table.
ROA Calculator
Calculate Return on Assets (ROA) as net income divided by average total assets — a key measure of how efficiently a company uses its asset base to generate profit.
ROAS Calculator
Calculate Return on Ad Spend (ROAS) as the ratio of ad-attributed revenue to ad spend. Enter optional COGS to see gross profit after advertising costs.
ROE Calculator
Calculate Return on Equity (ROE) as net income ÷ average shareholders' equity, with optional DuPont decomposition into margin, turnover and leverage.
投资回报率计算器
以百分比计算投资回报率 (ROI)、净收益或损失,以及在你的持有期内的年化回报。
ROIC Calculator
Calculate Return on Invested Capital (ROIC) as NOPAT divided by invested capital — the gold-standard metric for assessing whether a business creates or destroys shareholder value.
ROS Calculator
Calculate Return on Sales (ROS): operating profit divided by net revenue, expressed as a percentage — the operating margin.
Roth IRA Calculator
Project your Roth IRA balance at retirement. Enter annual contribution, current balance, expected return and years to see tax-free growth.
RSI Calculator
Calculate the Relative Strength Index (RSI) from average gain and average loss over a period — with overbought/oversold signal zones.
Rule of 72 Calculator
Estimate how many years it takes to double money at a fixed rate using the Rule of 72 — plus the exact doubling time.
RV Loan Calculator
Calculate your monthly RV loan payment, total interest and full cost of ownership from the price, down payment, APR and loan term.
SaaS LTV Calculator
Calculate the gross-margin-adjusted customer lifetime value (LTV) of a SaaS product from ARPU, monthly churn, and gross margin.
SaaS Metrics Calculator
Calculate core SaaS metrics: MRR, ARR, customer LTV, LTV:CAC ratio and CAC payback period from your subscription data.
Sabbatical Calculator
Calculate how much money you need to take a sabbatical: living costs, emergency buffer, savings shortfall and months until you can go.
薪资计算器
使用你的每周工时和每年工作周数,在时薪、周薪、月薪和年薪数字之间转换薪酬。
Salary Inflation Calculator
Find out if your salary has kept pace with inflation. Enter your base pay, years elapsed, and inflation rate to see your required salary and lost purchasing power.
Salary to Hourly Calculator
Convert an annual, monthly, or weekly salary to an hourly rate. Enter your pay and working hours to see hourly, daily, weekly and monthly breakdowns.
Salary with Overtime Calculator
Calculate weekly and annual pay including overtime — enter hourly rate, regular hours, overtime hours and the overtime multiplier.
Sales Calculator
Calculate total revenue, gross profit, profit margin and markup from selling price, cost price and units sold.
Sales Commission Calculator
Calculate commission earned on any sales amount and total pay including base salary — supports any flat commission rate.
销售税计算器
将销售税加到价格上,或从含税总额中提取税款,显示净价、税额和含税价。
储蓄目标计算器
看看你的储蓄通过定期每月存款和复利将如何增长,包括总供款和已赚取的利息。
Savings Goal Calculator
Find the periodic contribution needed to hit a savings goal by a target date, factoring in compound interest.
Savings Interest Rate Calculator
Calculate the annual interest rate required to grow savings to a target balance with regular monthly contributions.
Savings Plan Calculator
Calculate the future value of a savings plan: an initial deposit plus regular contributions growing with compound interest.
Savings Withdrawal Calculator
Find how much you can withdraw per period from savings, or how long savings will last at a given withdrawal rate with compound interest.
Scrap Gold Calculator
Calculate the melt value and scrap payout of gold jewellery or coins by weight, karat, and the current spot price per troy ounce.
Scrap Silver Calculator
Calculate the melt value and dealer scrap payout of silver jewellery, cutlery or coins by weight, hallmark purity, and the current spot price per troy ounce.
Second Stimulus Check Calculator
Estimate the second federal stimulus check (EIP-2, $600 per adult) based on your 2019 AGI, filing status and qualifying children.
Sell-Through Rate Calculator
Calculate sell-through rate: what percentage of received inventory was sold, plus optional revenue and gross profit.
Semi-Monthly Pay Calculator
Convert annual salary to semi-monthly (twice-a-month) gross and net pay, with tax and deduction breakdown.
Sharpe Ratio Calculator
Calculate the Sharpe ratio: excess portfolio return above the risk-free rate divided by portfolio volatility (σ).
Silver Melt Value Calculator
Calculate the intrinsic melt value of silver coins, bars or jewellery from weight, purity and the spot price.
单利计算器
为某个本金、利率和时间段计算单利和总额。
Simple Mortgage Calculator
Calculate your monthly mortgage payment, total interest paid and remaining balance using the standard amortisation formula.
Simple Savings Calculator
Calculate how much your savings will grow with regular monthly contributions and compound interest over any period.
Sinking Fund Calculator
Calculate the equal periodic deposit needed to accumulate a target lump sum by a set date, accounting for compound interest earned.
SIP Calculator
Calculate the maturity corpus of a monthly SIP in Indian mutual funds, with invested vs gains breakdown and month-by-month growth.
Smoker's CTC Calculator
Estimate the total additional annual cost (CTC) a smoking employee imposes on an employer: smoke-break productivity loss, healthcare premium surcharge, and extra sick days.
Software Contract Value Calculator
Calculate TCV, ACV, ARR, MRR and LTV for a SaaS or software contract from seats, price per seat, term, and discount.
Sortino Ratio Calculator
Calculate the Sortino ratio — a risk-adjusted return metric that penalises only downside volatility, unlike the Sharpe ratio.
Spending Multiplier Calculator
Calculate the Keynesian spending multiplier and total GDP impact of an initial government or investment injection from MPC.
SSY Calculator
Calculate the maturity value of India's Sukanya Samriddhi Yojana account — annual deposits, compound interest, total interest earned.
State Income Tax Calculator (USA, 2024)
Estimate your US state income tax for 2024 across all 50 states and D.C. — effective rate, marginal rate, and after-tax income.
Stimulus Check $40k Cap Calculator
Estimate stimulus check size under a hypothetical $40,000 AGI phase-out scenario — editable payment amounts and phase-out rate.
Stimulus Payment Calculator
Estimate your US stimulus check for any of the three COVID-19 rounds (CARES, Dec 2020, ARP) based on filing status, AGI and dependents.
Stock Average Cost Calculator
Calculate the weighted average cost per share across multiple purchase lots — ideal for dollar-cost averaging and averaging-down strategies.
Stock Beta Calculator
Calculate a stock's CAPM required return: E(r) = Rf + β × (Rm − Rf). Plot the Security Market Line.
Stock Profit & Loss Calculator
Calculate profit or loss on a stock trade — enter shares, buy and sell price and commissions to get net gain, return, and annualized return.
Stock Split Calculator
Calculate your new share count and adjusted price after a stock split or reverse split — total portfolio value is always preserved.
Student Loan Calculator
Calculate monthly student loan payments, total interest, and overall cost from your balance, annual rate, and repayment term.
Student Loan Forgiveness Calculator
Estimate how much of your federal student loan will be forgiven under PSLF (10 years) or income-driven repayment (20–25 years) based on your income and family size.
Student Loan Payment Calculator
Calculate monthly student loan payments accounting for the grace period — see how unpaid grace-period interest capitalizes into principal and raises the total cost.
Student Loan Repayment Calculator (US)
Compare US federal student loan repayment plans side by side: Standard 10-year, Extended 25-year, and Income-Driven Repayment — monthly payments and total cost.
Subscription Waste Calculator
Find how much money you waste each year on unused subscriptions — enter your total spend and how many services you actually use.
Sustainable Growth Rate Calculator (SGR)
Calculate the maximum sustainable growth rate a company can achieve without changing its financial structure or issuing new equity.
SWP Calculator
Calculate how long your investment corpus lasts with a fixed monthly withdrawal and expected annual return rate.
实得工资计算器
使用你自己的有效税率,根据税前收入估算实得(税后)工资。与国家无关:适用于任何薪资、支付频率和扣除项。
Tax Bracket Calculator
Calculate your 2024 US federal income tax, effective tax rate, and per-bracket breakdown from gross income, filing status, and deduction.
Taxable Equivalent Yield Calculator
Calculate the taxable equivalent yield of a tax-exempt bond (municipal bond) to compare it fairly with taxable bonds at your marginal tax rate.
Taylor Rule Calculator
Calculate the Taylor Rule benchmark policy interest rate from current inflation, output gap, neutral rate and coefficients.
TDS on Interest Calculator
Calculate TDS deducted on bank FD / savings interest under Section 194A for FY 2024-25 — with senior-citizen threshold and PAN/non-PAN rates.
定期存款计算器
计算定期(固定)存款的到期价值和利息 — 支持按月、按季度或按年复利,以及可选的利息税。
Texas Overtime Calculator
Calculate Texas overtime pay: federal FLSA rules apply — time and a half (1.5×) for hours over 40 per workweek, with no Texas state income tax.
Texas Sales Tax Calculator
Calculate Texas sales tax — 6.25% state rate plus up to 2% local, combined maximum 8.25%. Enter price and local rate for the total cost.
Time and a Half Calculator
Calculate time-and-a-half overtime pay: enter your hourly rate, regular hours and overtime hours to get total earnings.
Time Value of Money Calculator
Calculate the future value of a lump sum and regular payments at any annual interest rate using the standard TVM formula.
Times Interest Earned (TIE) Ratio Calculator
Calculate the Times Interest Earned ratio (EBIT ÷ Interest Expense) to assess a company's ability to service its debt from operating profit.
Total Asset Turnover Calculator
Calculate total asset turnover ratio — how efficiently a company uses its assets to generate revenue. Formula: Revenue ÷ Average Assets.
Treynor Ratio Calculator
Calculate the Treynor ratio — a portfolio's excess return per unit of systematic (market) risk (beta). Compare risk-adjusted performance across portfolios.
Triple Discount Calculator
Apply three successive percentage discounts to a price and find the final amount, total savings, and the equivalent single discount rate.
TRIR Calculator
Calculate OSHA's Total Recordable Incident Rate (TRIR) and benchmark your workplace safety against US industry averages.
True Cost of Real Estate Commission Calculator
See what a real estate commission truly costs — as a share of your equity, per year held, and the home appreciation needed just to break even.
Trump Tariff Calculator
Estimate the cost of 2025 Trump tariffs on imported goods. Select a tariff category (10% baseline, 25% Canada/Mexico, 145% China) or enter a custom rate.
Trump Tax Calculator
Estimate 2025 US federal income tax using TCJA brackets (10%–37%). Enter income and filing status to see tax owed, effective rate and bracket breakdown.
TTM Calculator
Calculate the trailing twelve months (TTM) total for revenue, earnings, EBITDA or any financial metric from the four most recent quarters.
UK Capital Gains Tax Calculator
Estimate UK Capital Gains Tax on shares, property or business assets using 2025/26 rates (18%/24%), with annual exempt amount and BADR.
UK Coin Weight Calculator
Calculate the total weight and monetary value of any mix of UK coins (1p–£2) using Royal Mint 2024 specifications.
UK National Insurance Calculator 2024–25
Calculate UK National Insurance contributions for employees (Class 1) and self-employed (Class 4) using 2024–25 thresholds and rates.
UK Stamp Duty (SDLT) Calculator
Calculate Stamp Duty Land Tax (SDLT) for residential property purchases in England and Northern Ireland — standard, first-time buyer and additional-property rates.
Unemployment Benefit Calculator
Estimate weekly and total unemployment benefits from your wages using a replacement rate — with presets for US, UK, Germany, France, Canada and more.
Unemployment Rate Calculator
Calculate the unemployment rate from the number of unemployed and employed people using the official ILO formula.
Unlevered Beta Calculator
Strip out financial leverage to find a company's unlevered (asset) beta using the Hamada equation: βU = βL ÷ (1 + (1−t) × D/E).
Unlevered Free Cash Flow Calculator (UFCF / FCFF)
Calculate unlevered free cash flow (FCFF) from EBIT, tax rate, D&A, working capital changes and CapEx — the key input for DCF valuation.
Unpaid Work Calculator
Calculate the monetary value of unpaid household work, childcare and caregiving using a market replacement-cost approach.
US Income Percentile Calculator
Find your US income percentile for individual or household income using 2022 IRS and Census data — see how your earnings compare to all Americans.
VA Disability Calculator
Calculate your VA combined disability rating using the VA whole-person method — not a simple sum. Enter up to 5 service-connected ratings and see each step.
VA Loan Calculator
Calculate your VA home loan monthly payment including the VA funding fee. Supports first/subsequent use, regular and Reserve/Guard service types, and disability exemptions.
Value at Risk (VaR) Calculator
Calculate Value at Risk (VaR) and Expected Shortfall (CVaR) for a portfolio using the parametric normal-distribution method at 90–99.9 % confidence.
Variable Annuity Calculator
Project the future value of a variable annuity and estimate monthly retirement income from contributions and an assumed market return.
增值税 (VAT) 计算器
将 VAT 加到净价上,或从含税价中扣除 VAT,为任意 VAT 税率显示净额、VAT 和含税总额。
Velocity of Money Calculator
Calculate the velocity of money (V = GDP ÷ M2) and explore the Fisher equation linking money supply, velocity, prices and output.
WACC Calculator
Calculate WACC (Weighted Average Cost of Capital) from equity and debt values, cost of equity, pre-tax cost of debt and the corporate tax rate.
Calculate WACC using equity and debt market values, cost of equity (CAPM), pre-tax cost of debt, and the corporate tax rate for the interest tax shield.
Wage Calculator
Convert any wage or salary between hourly, daily, weekly, bi-weekly, monthly and annual figures, with estimated net take-home after tax.
Wage to Salary Calculator
Convert an hourly wage to an annual salary — accounting for overtime, paid leave, employer benefits and an estimated income-tax rate.
Website Ad Revenue Calculator
Estimate website advertising revenue from CPM display ads and CPC click earnings based on pageviews, CPM rate, CTR and cost per click.
Wedding Budget Calculator
Allocate your wedding budget across venue, catering, photography, decor, music and attire — see each category amount and a visual breakdown.
Week-Over-Week Calculator
Calculate the week-over-week percentage change between two values — shows absolute change and WoW % for any metric or KPI.
Weekly Pay Calculator
Calculate gross weekly pay from an hourly rate, regular hours and overtime hours — supports any overtime multiplier including time-and-a-half.
What to Offer on a House Calculator
Estimate a smart offer price on a home based on market conditions, property condition, days on market, and comparable sales.
Working Capital Calculator
Calculate working capital (current assets minus current liabilities) and the current ratio to assess short-term financial health.
Working Capital Turnover Ratio Calculator
Calculate the working capital turnover ratio from net revenue and opening/closing current assets and liabilities to measure operational efficiency.
Year-Over-Year Growth Calculator
Calculate year-over-year (YoY) growth rate as a percentage. Enter this year's and last year's value for any metric — revenue, users, sales or KPIs.
Yearly Wage Calculator
Calculate your annual (yearly) gross wage from an hourly, daily, weekly or monthly rate. Adjust hours, days and weeks for your actual schedule.
Yield to Call Calculator (YTC)
Calculate the yield to call of a callable bond from its price, coupon rate, call price and years to the call date.
Yield to Maturity Calculator (YTM)
Calculate the yield to maturity of a bond from its price, coupon rate, face value and years to maturity — annual, semiannual or quarterly coupons.
YouTube Money Calculator
Estimate monthly and annual YouTube earnings from RPM, channel views, sponsorships and memberships. Based on your YouTube Studio RPM.
Zakat Calculator
Calculate your annual Zakat obligation: 2.5% of net zakatable wealth above the gold or silver nisab threshold.
20-20-20 Rule Calculator
Calculate how many eye-rest breaks you need based on the 20-20-20 rule: every 20 minutes look 20 feet away for 20 seconds.
4Ts Score Calculator
Calculate the 4Ts score (Warkentin) to estimate the pre-test probability of heparin-induced thrombocytopenia (HIT) — 0–3 low, 4–5 intermediate, 6–8 high.
5/3/1 Lifting Calculator
Calculate Jim Wendler's 5/3/1 powerlifting program working sets from your one-rep max — all four weeks including deload.
5K Pace Calculator
Calculate your 5K running pace in min/km and min/mile, speed in km/h and mph, and cumulative kilometre split times from a finish time.
6-Minute Walk Test Calculator
Calculate your 6-minute walk test distance as a percentage of the age/sex/height/weight-predicted normal using the Enright & Sherrill equations.
90-Minute Sleep Cycle Calculator
Find the best bedtime or wake-up time by timing your sleep to complete full 90-minute cycles — wake refreshed instead of mid-cycle.
A Body Shape Index (ABSI) Calculator
Calculate ABSI, a measure that captures abdominal obesity beyond BMI by combining waist circumference, height and weight.
A-a Gradient Calculator (Alveolar-Arterial Oxygen Gradient)
Calculate the alveolar-arterial (A-a) oxygen gradient from arterial blood gas values to distinguish V/Q mismatch from hypoventilation.
ABI Calculator
Calculate the Ankle-Brachial Index (ABI) from ankle and arm systolic pressures to screen for peripheral arterial disease (PAD).
Absolute Eosinophil Count Calculator
Calculate the absolute eosinophil count (AEC) from WBC and eosinophil percentage and classify normal vs. eosinophilia severity.
ACFT Calculator
Calculate your Army Combat Fitness Test (ACFT) score for all six events and see your total out of 600.
Acid-Base Calculator
Calculate arterial pH from bicarbonate and PaCO₂ using Henderson-Hasselbalch and classify the acid-base disturbance.
ACR Calculator
Calculate the urine albumin-to-creatinine ratio (ACR) from a spot urine sample to assess kidney health and CKD albuminuria category.
ACR TI-RADS Thyroid Nodule Calculator
Score thyroid nodule ultrasound features using ACR TI-RADS 2017 to stratify malignancy risk and guide FNA decisions.
Addiction Cost Calculator
Estimate the financial and time cost of a daily habit: daily, monthly, and annual spend plus hours per year consumed by the habit.
Adjusted Age Calculator
Calculate the corrected (adjusted) age of a premature baby by subtracting weeks born early from the chronological age.
Adjusted Body Weight Calculator
Calculate adjusted body weight (AdjBW) for drug dosing in obese patients using IBW + 0.4 × (ABW − IBW) — Devine formula for IBW.
Adrenal Washout Calculator
Calculate CT adrenal washout percentages (APW and RPW) to help characterise adrenal incidentalomas as adenoma or non-adenoma.
AFT Calculator
Estimate VO₂max from the Queens College Step Test 3-minute protocol — enter your 15-second post-exercise pulse count to get your aerobic fitness category.
Age-Adjusted D-Dimer Calculator
Calculate the age-adjusted D-dimer threshold for PE exclusion. Patients ≥50 use age × 10 μg/L FEU instead of the standard 500 μg/L cut-off.
AHI Calculator
Calculate the Apnea-Hypopnea Index (AHI) from a sleep study and classify sleep apnea severity per AASM guidelines.
Air Force PT Calculator
Calculate your US Air Force Physical Fitness Assessment (PFA) composite score for the 1.5-mile run, push-ups and abdominal circumference.
Albumin-Globulin (A/G) Ratio Calculator
Calculate the albumin-to-globulin (A/G) ratio from serum albumin and total protein — useful for interpreting liver, kidney and immune function tests.
Alcohol Units Calculator
Calculate alcohol units in any drink from ABV and volume, and compare to UK weekly low-risk guidelines.
Aldrete Score Calculator
Calculate the modified Aldrete score to assess patient readiness for discharge from the Post-Anaesthesia Care Unit (PACU).
Alvarado Score Calculator
Calculate the Alvarado (MANTRELS) score to estimate the probability of acute appendicitis — 8 clinical and lab criteria, 0–10 scale.
Alzheimer's Life Expectancy Calculator
Estimate median survival after an Alzheimer's disease diagnosis by age and sex, based on published cohort data. For educational use.
Anaerobic Threshold Calculator
Estimate your anaerobic threshold heart rate and 5-zone training ranges from age and resting heart rate using the Karvonen Heart Rate Reserve method.
ANC Calculator
Calculate the Absolute Neutrophil Count (ANC) from a CBC differential and classify neutropenia severity.
ANC Without Bands Calculator
Calculate the Absolute Neutrophil Count (ANC) using only segmented neutrophils — excluding band cells — from a CBC differential and interpret the result.
Anion Gap Calculator
Calculate the anion gap and albumin-corrected anion gap from serum Na⁺, Cl⁻, and HCO₃⁻ with interpretation guidance.
Aortic Valve Area Calculator (Gorlin Formula)
Calculate aortic valve area from cardiac output, heart rate, systolic ejection period, and mean pressure gradient using the Gorlin formula.
APACHE II Score Calculator
Calculate the APACHE II score from 12 physiological variables, age, and chronic health to estimate ICU severity and predicted hospital mortality.
Ape Index Calculator
Calculate your ape index (arm span minus height) and ape ratio (arm span ÷ height) — commonly used in rock climbing, swimming, and sports science.
APGAR Score Calculator
Calculate the APGAR score for newborn assessment at 1 and 5 minutes after birth using the five standard criteria: Appearance, Pulse, Grimace, Activity, and Respiration.
APRI Calculator
Calculate the APRI score (AST-to-Platelet Ratio Index) to estimate the probability of liver fibrosis and cirrhosis.
Arterial Age Calculator
Estimate vascular (arterial) age and 10-year coronary heart disease risk using the Framingham Point Score (NCEP ATP III, 2002).
Arterial Blood pH Calculator
Enter arterial pH, PaCO₂ and HCO₃⁻ to classify the acid-base disorder, verify Henderson-Hasselbalch consistency and assess compensation.
AST/ALT Ratio Calculator
Calculate the AST/ALT (De Ritis) ratio to help differentiate alcoholic liver disease from viral hepatitis and NAFLD.
AUDIT Calculator
Complete the validated WHO 10-question AUDIT questionnaire, get your score (0–40), and see your risk zone with the recommended clinical intervention.
AUDIT-C Calculator
Screen for hazardous alcohol use with the validated 3-question AUDIT-C tool. Get your score (0–12) and see whether it meets the clinical positive-screen threshold.
Average Triathlon Finish Times Calculator
Estimate your triathlon finish time from swim, bike and run paces and compare to typical age-group averages for sprint, Olympic, 70.3 and full Ironman.
Baby Eye Color Calculator
Predict your baby's eye color probability from both parents' eye colors using a simplified Mendelian genetics model.
Baby Formula Calculator
Calculate how much baby formula to prepare per feeding and per day based on your baby's weight.
Baby Percentile Calculator
Find your baby's weight and length percentile on WHO 2006 growth standards for boys and girls aged 0–24 months.
Baby's Milk Intake Calculator
Find the recommended daily milk intake for your baby by age (0–24 months) and check whether their current intake is in the normal range.
BAC Calculator
Estimate your blood alcohol concentration (BAC) using the Widmark formula. Enter drinks, weight, sex and time elapsed.
Back to Normal Life Calculator
Estimate how many days until you return to your normal routine after illness or surgery, based on your current rate of recovery.
BAI Calculator
Calculate your Body Adiposity Index (BAI) — an estimate of body fat percentage from hip circumference and height, requiring no scale.
Barthel Index Calculator
Calculate the Barthel Index (0–100) to assess functional independence in daily activities — feeding, mobility, continence and more.
BASDAI Calculator
Calculate the BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) score from 6 patient-reported questions on a 0–10 scale.
Batting Average Calculator
Calculate batting average for baseball (hits ÷ at-bats) or cricket (runs ÷ dismissals), with performance tier ratings.
Batting Strike Rate Calculator
Calculate cricket batting strike rate (runs per 100 balls) for T20, ODI and Test formats with benchmark ratings.
BBT Calculator
Analyse your basal body temperature (BBT) reading against your follicular baseline to detect the post-ovulation thermal shift and estimate cycle phase.
BED Calculator
Calculate Biologically Effective Dose (BED) and EQD2 for any radiation therapy fractionation schedule using the linear-quadratic model.
BEE Calculator
Estimate Basal Energy Expenditure using the revised Harris-Benedict equation with optional stress and activity factors for clinical nutrition.
Beighton Score Calculator
Screen for generalised joint hypermobility using the 9-point Beighton score. Answer 9 yes/no questions and see your score with clinical interpretation.
Bench Press Calculator
Estimate your bench press 1-rep max from any weight and rep count using five proven formulas (Epley, Brzycki, Mayhew and more).
Bench Press Pyramid Calculator
Generate a complete bench press pyramid workout (ascending, descending or full) from your 1RM — with exact loads, reps and total training volume per session.
Benzodiazepine Conversion Calculator
Convert between benzodiazepine doses using diazepam equivalents from the Ashton Manual. For reference only — not a substitute for clinical advice.
Berg Balance Scale Calculator (BBS)
Score all 14 Berg Balance Scale items (0–4 each, max 56) and instantly see fall-risk category: high (0–20), moderate (21–40) or low (41–56).
Bicarbonate Deficit Calculator
Calculate the HCO₃ deficit in mEq for metabolic acidosis using the standard 0.4 × weight × (target − actual) formula.
Bicycle Chain Length Calculator
Calculate the correct bicycle chain length in links and millimetres from chainstay length and chainring/cassette size using the Park Tool formula.
Bike Cadence and Speed Calculator
Find the pedalling cadence needed to reach a target cycling speed for any gear and wheel size — with a cadence–speed curve.
Bike Cadence Calculator
Calculate your cycling speed from pedalling cadence, gear ratio and wheel circumference — see which RPM zone you are in.
Bike Gear Calculator
Calculate cycling gear ratio, gear development (m/rev) and gain ratio from chainring teeth, cog teeth, wheel circumference and crank length.
Bike Pace Calculator
Calculate your average cycling speed and pace (min/km) from distance and time — with projected finish times for common cycling distances.
Bike Size Calculator
Find the right road, mountain or city bike frame size from your inseam and height — with saddle height and size category.
Bike Speed Calculator
Calculate average cycling speed in km/h and mph, pace per km and mile, from ride distance and time.
Biking Life Gain Calculator
Estimate how many years of life regular cycling adds based on the 2016 PLOS Medicine meta-analysis — enter weekly ride time and intensity.
BIMS Calculator
Score the Brief Interview for Mental Status (BIMS), a CMS MDS 3.0 cognitive screening tool used in nursing homes — three parts, total 0–15.
Birth Control Cost Calculator
Calculate the total, annual, and daily cost of any birth control method from monthly fees and any one-time upfront cost.
Birth Weight Percentile Calculator
Estimate a newborn's birth weight percentile by gestational age and sex using approximate Fenton 2013 / INTERGROWTH-21st reference ranges.
Bishop Score Calculator
Calculate the Bishop score for cervical ripeness before labour induction — scoring dilation, effacement, fetal station, consistency and position (0–13).
Bladder Volume Calculator
Estimate bladder volume from 3-D ultrasound measurements (length, width, depth) using the validated ellipsoidal formula V = 0.52 × L × W × H.
Blood Donor Compatibility Calculator
Find which blood types are compatible for donation and transfusion based on ABO and Rh factor — for whole blood / red blood cells.
Blood Loss Calculator
Estimate acute blood loss from haemoglobin drop using the Gross formula and classify severity by ATLS haemorrhage class.
Blood Pregnancy Test Calculator
Calculate beta-hCG doubling time from two blood test results to assess early pregnancy viability. Normal: doubles every 48–72 hours.
Blood Pressure Calculator
Enter systolic and diastolic readings to get AHA/ACC 2017 blood pressure classification, mean arterial pressure, and pulse pressure.
Blood Sugar Calculator
Convert blood glucose between mg/dL and mmol/L, classify fasting or post-meal readings per ADA 2024, and estimate HbA1c.
Blood Type Calculator
Find out which blood types you can donate to or receive from, and see possible child blood types from two parents.
Blood Volume Calculator
Estimate total blood volume in litres using Nadler's equation from height, weight and sex — used clinically before surgery or transfusion.
BMI 计算器
根据身高和体重计算你的身体质量指数 (BMI),并给出 WHO 体重类别。
BMI Calculator for Kids
Calculate BMI-for-age percentile for children and teens aged 2–20 using CDC 2000 growth chart LMS method, with weight category.
BMI Calculator for Men
Calculate BMI for men with WHO weight category, healthy weight range for your height, and estimated body fat % using the Deurenberg formula.
BMI Calculator for Women
Calculate BMI for women using the standard WHO formula and optionally assess cardiovascular risk from waist circumference using WHO women's thresholds (80/88 cm).
BMI for Teens Calculator
Calculate BMI for children and teenagers aged 2–20 using CDC age- and sex-adjusted percentile categories: underweight, healthy, overweight, or obese.
BMI in Pregnancy Calculator
Calculate pre-pregnancy BMI and personalised gestational weight-gain targets using IOM 2009 guidelines for single and twin pregnancies.
BMI Percentile Calculator for Children
Calculate a child's BMI-for-age percentile and z-score using CDC 2000 LMS growth charts for ages 2–20, with bell-curve visualisation.
BMI Weight Loss Calculator
Find the target weight needed to reach a goal BMI and estimate how many weeks it will take at different daily calorie deficits.
BMR 与热量计算器
使用 Mifflin-St Jeor 公式估算你的基础代谢率 (BMR) 和每日热量需求。
BMR Calculator
Calculate Basal Metabolic Rate using the original (1918) or revised (1984 Roza–Shizgal) Harris-Benedict equation, then multiply by an activity factor to get TDEE.
Calculate Basal Metabolic Rate using the Katch-McArdle formula — the only BMR equation based on lean body mass rather than total weight, making it more accurate for athletes.
BODE Index Calculator
Calculate the BODE index for COPD severity using BMI, FEV₁%, mMRC dyspnea scale and 6-minute walk distance.
体脂计算器
使用美国海军围度法,根据以厘米为单位的颈围、腰围、臀围和身高测量值估算你的体脂百分比。
Body Frame Size Calculator
Determine your body frame size (small, medium or large) from height and wrist circumference using the height-to-wrist ratio.
Body Shape Calculator
Find your body shape (hourglass, pear, apple, rectangle, inverted triangle) from bust, waist and hip measurements.
体表面积计算器
使用简单而准确的 Mosteller 公式,根据身高和体重以平方米计算体表面积 (BSA)。
Body Water Calculator
Estimate total body water (TBW) in litres and as a percentage of body weight using the Watson formula for men and women.
Bowling Average Calculator
Calculate your bowling average from game scores — see your high game, low game and pin total across any number of sessions.
Braden Scale Calculator
Calculate the Braden Scale score to assess a patient's risk of pressure injuries (bedsores) across six clinical subscales.
Breast Cancer Recurrence Risk Calculator
Estimate breast cancer recurrence risk and 10-year survival using the validated Nottingham Prognostic Index (NPI) from tumour size, grade and node stage.
Breast Cancer Risk Calculator
Estimate your 5-year breast cancer risk using a simplified Gail model based on age, family history, menstrual history and prior biopsies.
Breast Pump Flange Size Calculator
Find the correct breast pump flange (shield) size from your nipple diameter — the right fit improves milk output and comfort.
Breastfeeding Calorie Calculator
Calculate how many extra calories you need while breastfeeding using IOM guidelines and the Mifflin-St Jeor equation for your TDEE.
BRI Calculator
Calculate your Body Roundness Index (BRI) from height and waist circumference — a shape-based body fat estimate that outperforms BMI.
Bruce Protocol METs & VO₂max Calculator
Estimate VO₂max and METs from a Bruce Protocol treadmill exercise test using the Bruce (1973) and McConnell & Clark (1987) regression equations.
BSA Calculator
Calculate body surface area (BSA) in m² using the Mosteller, Du Bois, or Haycock formula — with a side-by-side comparison of all three.
BUN Creatinine Ratio Calculator
Calculate the BUN-to-creatinine ratio from a metabolic panel to help distinguish pre-renal, renal, and post-renal azotemia.
Burpee Calorie Calculator
Estimate calories burned doing burpees based on body weight, repetitions, and pace — using MET values from the Compendium of Physical Activities.
Caffeine Calculator
Estimate the caffeine remaining in your body using exponential decay with a 5.7-hour average half-life.
CAGE Questionnaire Calculator
Screen for alcohol use disorder using the validated 4-question CAGE questionnaire. A score of 2 or more warrants professional evaluation.
Calorie Calculator
Calculate daily calories for weight loss, maintenance or muscle gain using the Mifflin-St Jeor BMR equation and your activity level.
热量缺口计算器
计算减重所需的每日卡路里目标。输入你的维持热量 (TDEE) 和每周目标,即可得到安全的每日摄入量和热量缺口。
卡路里消耗计算器
使用《身体活动概要》中的 MET 值估算运动期间消耗的卡路里。选择一项活动,输入你的体重和时长。
Car Heat Calculator
Estimate how hot a parked car gets after any number of minutes in the sun, with danger-level rating for children, pets and the elderly.
Carb Calculator
Calculate daily carbohydrate, protein and fat grams from a calorie target and macro split percentage.
Carboplatin Dose Calculator
Calculate carboplatin chemotherapy dose using the Calvert formula and Cockcroft-Gault creatinine clearance estimate.
Cardiac Index Calculator
Calculate cardiac index (CI) and cardiac output (CO) from heart rate, stroke volume and body surface area using the Mosteller formula.
Cardiac Output Calculator
Calculate cardiac output (CO) and cardiac index (CI) from heart rate and stroke volume using CO = HR × SV.
CDAI Calculator
Calculate the Crohn's Disease Activity Index (CDAI) from stool count, pain, well-being, labs and physical findings. Classifies remission to severe disease.
Centor Score Calculator
Calculate the modified Centor (McIsaac) score to estimate Group A strep throat probability and guide antibiotic decisions.
Cerebral Perfusion Pressure (CPP) Calculator
Calculate cerebral perfusion pressure (CPP = MAP − ICP) from systolic BP, diastolic BP and intracranial pressure, with clinical interpretation.
CHA₂DS₂-VASc Calculator
Calculate the CHA₂DS₂-VASc score to estimate annual ischaemic stroke risk in atrial fibrillation and guide anticoagulation decisions.
Charlson Comorbidity Index (CCI) Calculator
Calculate the age-adjusted Charlson Comorbidity Index (CCI) from patient age and weighted comorbid conditions. Estimates 10-year survival probability.
Child Height Percentile Calculator
Estimate a child's height percentile by age and sex using approximate CDC 2000 growth chart reference values (ages 2–20).
Child Weight Percentile Calculator (WHO 0–60 Months)
Find a child's weight percentile and Z-score using the WHO Growth Reference (2006) for boys and girls aged 0–60 months.
Child-Pugh Score Calculator
Calculate the Child-Pugh score and class (A/B/C) for liver cirrhosis severity from bilirubin, albumin, INR, ascites, and encephalopathy.
Cholesterol Ratio Calculator
Calculate your key cholesterol ratios (TC/HDL, LDL/HDL, TG/HDL) and see how they map to cardiovascular risk ranges.
Cholesterol Units Calculator
Convert cholesterol and triglyceride readings between mmol/L (EU/UK) and mg/dL (US) for TC, HDL, LDL and TG.
Cigarette Calculator
Calculate the daily, monthly, annual, and lifetime cost of smoking, total cigarettes, and pack-years from your smoking habits.
Circadian Rhythm Calculator
Find the best times to wake up based on 90-minute sleep cycles so you rise feeling refreshed, not groggy.
CIWA-Ar Calculator
Score alcohol withdrawal severity using the validated CIWA-Ar scale (0–67). Assesses 10 symptom domains.
Clomid Ovulation Calculator
Estimate ovulation dates and fertile window during a Clomid (clomiphene) cycle using the days 3–7 or 5–9 protocol.
受孕日期计算器
根据你的末次月经或预产期,估算受孕日期,并给出几天的可能易孕受孕窗口。
Conception Date Calculator
Estimate your conception date from your baby's birth date by working backward 266 days (38 weeks). Shows the fertile window and estimated LMP.
Corrected Calcium Calculator
Correct serum calcium for low or high albumin using the Payne formula: Ca_corrected = Ca_measured + 0.8 × (4.0 − albumin).
Corrected Magnesium Calculator
Calculate albumin-corrected serum magnesium to reveal true Mg status in patients with low albumin (hypoalbuminemia).
Corticosteroid Equivalency Calculator
Convert between corticosteroid doses using standard anti-inflammatory equivalency: prednisone, dexamethasone, hydrocortisone and more.
COVID Event Risk Calculator
Estimate the probability that at least one infectious person is present at a gathering, using local prevalence and an ascertainment factor for unreported cases.
COVID-19 Mortality Risk Calculator
Estimate historical COVID-19 infection fatality rate by age, comorbidities and vaccination status using peer-reviewed IFR data.
CrCl Calculator
Estimate creatinine clearance (CrCl) using the Cockcroft-Gault formula and classify kidney function by CKD stage.
Creatinine Clearance Calculator (Cockcroft-Gault)
Estimate creatinine clearance (CrCl) and kidney function stage using the Cockcroft-Gault equation from age, sex, weight, and serum creatinine.
Cricket Follow-On Calculator
Determine whether a cricket team can enforce the follow-on based on first-innings scores and match duration under ICC Playing Conditions.
Crown-Rump Length (CRL) Calculator
Convert a crown-rump length (CRL) in mm to gestational age in weeks and days using the Robinson & Fleming formula.
CURB-65 Calculator
Calculate the CURB-65 score to estimate 30-day mortality risk in community-acquired pneumonia and guide admission decisions.
CVD Risk Calculator
Estimate your 10-year cardiovascular disease risk using the Framingham Risk Score from cholesterol, blood pressure, age, sex, smoking and diabetes.
Cycling Breakaway Calculator
Calculate whether a cycling breakaway will survive to the finish line based on gap, remaining distance, and breakaway vs peloton speed.
Cycling Heart Rate Zone Calculator
Calculate your 5 cycling heart rate training zones from max HR — with optional Karvonen (heart-rate-reserve) zones if you enter your resting HR.
Cycling Power Zones Calculator
Calculate all 7 Coggan cycling power training zones from your FTP (Functional Threshold Power) in watts and W/kg.
Cycling Wattage Calculator
Calculate the watts required to cycle at a given speed and gradient using a physics-based model of aerodynamic drag, rolling resistance, gravity and drivetrain loss.
每日热量计算器
使用 Mifflin-St Jeor 公式计算你的每日热量需求 (TDEE),并得出用于减重、维持或增重的目标热量。
Daily Protein Intake Calculator
Calculate how much protein you need per day based on body weight and goal — maintain weight, endurance sport, muscle building or weight loss. Based on ISSN 2017 guidelines.
DAPT Score Calculator
Calculate the DAPT score (Yeh et al. 2016) to guide the duration of dual antiplatelet therapy after PCI. Score ≥ 2 favours prolonged DAPT.
DASI Calculator
Calculate the Duke Activity Status Index (DASI) score to estimate functional capacity in METs and VO₂ peak from 12 self-reported activity questions.
Dead Space Calculator
Calculate anatomical or physiological pulmonary dead space, VD/VT ratio, alveolar ventilation and minute ventilation.
Denver HIV Risk Score Calculator
Calculate the Denver HIV Risk Score to identify patients who may benefit from HIV screening. Score ≥ 4 recommends testing.
Diabetes Risk Calculator
Estimate your 10-year risk of developing type 2 diabetes using the validated FINDRISC screening score (Lindström & Tuomilehto, 2003).
Diabetic Ketoacidosis (DKA) Calculator
Classify DKA severity and compute anion gap, corrected sodium, Winter's pCO₂, and effective osmolality from blood glucose, pH, and electrolytes.
DIC Syndrome Calculator
Calculate the ISTH overt DIC score from platelets, D-dimer, PT prolongation, and fibrinogen — educational use only.
Diet Risk Score Calculator
Assess your dietary risk across 6 WHO-aligned food factors — fruits & veg, whole grains, meat, sugar, fish, and sugary drinks.
DIN Ski Binding Calculator
Calculate the recommended DIN binding release setting based on weight, boot sole length, skier type and age (ISO 11088 simplified).
DIY Sports Drink Calculator
Calculate the exact sugar and salt amounts to make a homemade isotonic sports drink. Set your carbohydrate % and sodium target per batch.
DLBCL Prognosis Calculator
Calculate the International Prognostic Index (IPI) and Revised IPI (R-IPI) for diffuse large B-cell lymphoma prognosis.
Dog Walking Benefits Calculator
Calculate calories burned and miles walked from daily dog walks. Enter weight, pace, duration and frequency to see weekly and yearly fitness totals.
Doppler Echo Cardiac Output Calculator
Calculate cardiac output and cardiac index from Doppler echocardiography: LVOT diameter, VTI, and heart rate using the stroke-volume method.
Draw Length Calculator
Calculate your archery draw length from arm span using the AMO/ATA standard formula. Get the right bow fit first time.
DRI Calculator
Look up the NIH Dietary Reference Intake (RDA/AI) for protein, fibre, vitamins, and minerals by age and sex.
Drip Rate Calculator
Calculate the IV infusion drip rate in drops per minute (gtts/min) and flow rate (mL/hr) from volume, time and drop factor.
Drops per Minute Calculator
Calculate how many drops per minute to count when regulating a gravity IV drip set, from the ordered mL/hr rate and drop factor.
Duckworth-Lewis Calculator
Calculate the revised D/L target in cricket when overs are lost to rain. Uses the published 2002 Duckworth-Lewis resource model coefficients.
DUDIT Calculator
Screen for drug use disorders with the validated 11-question DUDIT tool. Get your score (0–44) and see if it meets the clinical positive-screen threshold.
Duke Activity Status Index (DASI) Calculator
Estimate your functional capacity in METs from the 12-item Duke Activity Status Index questionnaire — used in cardiac risk assessment.
Dunk Calculator
Calculate the vertical jump you need to dunk a basketball based on your height, standing reach and rim height.
E-bike Range Calculator
Estimate your electric bike range from battery size, speed, rider weight, terrain and assist level using physics-based energy modelling.
EASI Score Calculator
Calculate the EASI score for atopic dermatitis severity across four body regions with intensity and area scoring.
ECG Boxes to Seconds Calculator
Convert ECG grid boxes to seconds or milliseconds at 25 or 50 mm/s, and calculate heart rate from the RR interval box count.
ECG Heart Rate Calculator
Calculate heart rate in bpm from an ECG strip using the RR interval, the 1500 rule, or the 6-second strip count method.
EDD Calculator
Calculate your estimated due date and current pregnancy week using Naegele's rule, adjusted for your personal cycle length.
EER
Calculate your Estimated Energy Requirement (EER) using the IOM 2002 DRI equations for adults, with adjustments for activity level, pregnancy, and lactation.
eGFR Calculator
Estimate your kidney filtration rate (eGFR) using the CKD-EPI 2021 race-free equation from serum creatinine, age, and sex.
Egg Freezing Calculator
Estimate how many mature oocytes to freeze to achieve a target probability of at least one live birth, based on age-group success rates from published fertility data.
Elliptical Calorie Calculator
Estimate calories burned on an elliptical trainer from body weight, session duration and effort level using MET values.
ELO Rating Calculator
Calculate your new ELO rating and points gained or lost after a match using the standard ELO formula for win, draw, or loss.
EORTC Bladder Cancer Calculator
Calculate the EORTC recurrence (0–17) and progression (0–23) scores for non-muscle-invasive bladder cancer per Sylvester 2006.
EPDS Calculator
Score the Edinburgh Postnatal Depression Scale (EPDS) across 10 questions. Threshold ≥ 10 flags possible perinatal depression.
Epworth Sleepiness Scale Calculator
Calculate your Epworth Sleepiness Scale (ESS) score across 8 everyday situations and classify daytime sleepiness severity (0–24).
ERA Calculator
Calculate a pitcher's Earned Run Average (ERA): earned runs allowed per 9 innings pitched, with MLB context bands.
Erg Calculator
Calculate power output, calories burned and distance for a rowing ergometer workout from your 500 m split time using the Concept2 formula.
EROA Calculator
Calculate effective regurgitant orifice area using the PISA method to grade mitral regurgitation severity from echocardiographic measurements.
Estimate Height in Bedridden Patients
Estimate standing height in bedridden or wheelchair-bound patients from knee height and age using the Chumlea 1985 formula.
Estimated Average Glucose Calculator
Convert HbA1c (%) to estimated average glucose (eAG) in mg/dL or mmol/L using the ADA-validated Nathan 2008 equation.
EtG Calculator
Estimate how long EtG (ethyl glucuronide) remains detectable in urine after alcohol consumption, based on drinks consumed and time elapsed.
ETT Size Calculator
Calculate endotracheal tube (ETT) internal diameter and insertion depth for paediatric patients by age (Motoyama formula) or neonatal weight.
Excessive Weight Gain in Pregnancy Calculator
Compare actual pregnancy weight gain with IOM 2009 recommendations by BMI category and gestational week — assess if gain is on track, below or above the guideline range.
Exclusive Pumping Calculator
Plan your exclusive pumping schedule: track daily milk output, compare with your baby's estimated needs, and see surplus, session timing and weekly totals.
Face Shape Calculator
Determine your face shape — oval, round, square, heart, diamond, or oblong — from four simple measurements.
Fagerström Test for Nicotine Dependence (FTND) Calculator
Complete the validated 6-question Fagerström Test and get your nicotine dependence score (0–10) with clinical guidance.
False Negative Pregnancy Test Calculator
Estimate the probability of a false negative pregnancy test at any DPO based on hCG levels and test sensitivity.
Fat Burning Zone Calculator
Find your fat-burning heart rate zone (60–70% of max HR) and all five training zones using three validated max HR formulas.
Fat Calculator
Calculate your daily fat intake in grams from total calories and a fat percentage target, with protein, carb, and saturated fat breakdowns.
Fatigue Severity Scale (FSS) Calculator
Score the validated 9-item Fatigue Severity Scale (FSS). A mean score ≥ 4 indicates clinically significant fatigue.
FENa Calculator
Calculate the Fractional Excretion of Sodium (FENa) from urine and plasma sodium and creatinine to differentiate pre-renal from intrinsic acute kidney injury.
Fertility by Age Calculator
Estimate the monthly and cumulative probability of conception by female age, based on published fecundability research and SART IVF data.
Fetal Weight Percentile Calculator
Calculate fetal weight percentile and SGA/AGA/LGA classification by gestational age using Hadlock 1991 log-normal reference standards.
FEUrea Calculator
Calculate fractional excretion of urea (FEUrea) to differentiate prerenal AKI from intrinsic renal injury — especially useful when the patient is on diuretics.
FEV1/FVC Ratio Calculator
Calculate the FEV1/FVC ratio from spirometry, determine obstructive vs restrictive patterns, and compare to ERS 1993 predicted values by age, sex, and height.
FFMI Calculator
Calculate your Fat-Free Mass Index (FFMI) and normalised FFMI from weight, height, and body fat percentage, with natural physique classification.
FIB-4 Calculator
Calculate the FIB-4 index from age, AST, ALT and platelet count to assess risk of advanced liver fibrosis non-invasively.
Fiber Calculator
Calculate your recommended daily fiber intake by age and sex, compare it to your current intake, and find high-fiber foods to close the gap.
Finnegan NAS Score Calculator
Calculate the Finnegan Neonatal Abstinence Syndrome (NAS) score across 21 CNS, metabolic/vasomotor/respiratory, and GI signs to guide treatment decisions for neonatal opioid withdrawal.
Fish Oil Calculator
Calculate your daily EPA and DHA omega-3 intake from fish oil supplements and see how it compares to AHA and FDA recommendations.
Fish Weight Calculator
Estimate the weight of a fish from its length and girth using the standard sport-fishing formula W = (L × G²) / 800.
Fishing Reel Line Capacity Calculator
Calculate how many yards of fishing line fit on a reel from spool OD, core diameter, width and line diameter.
FOC Calculator
Calculate the Front of Center (FOC) percentage for an arrow using length and balance point — essential for tuning accuracy and stability in archery.
FPCT Calculator
Calculate the Fractional Excretion of Phosphate (FE_PO4 / FPCT) to assess renal tubular phosphate handling and detect phosphate wasting or retention.
Frailty Index Calculator
Screen for frailty using the validated 5-item FRAIL Scale: fatigue, resistance, ambulation, illnesses, and weight loss.
Framingham Risk Calculator
Estimate 10-year cardiovascular disease risk using the NCEP ATP III Framingham Point Score (2001 tables).
Free Testosterone Calculator
Estimate free and bioavailable testosterone from total testosterone, SHBG and albumin using the Vermeulen 1999 quadratic formula.
Fundal Height Calculator
Calculate expected fundal height from gestational age, or estimate gestational age from a fundal height measurement using McDonald's rule (1 cm per week, 20–36 weeks).
GAA Calculator
Calculate a premature baby's corrected (adjusted) age by subtracting weeks born early from their chronological age.
GAD-7 Anxiety Calculator
Score the GAD-7 questionnaire to screen for generalized anxiety disorder severity: minimal, mild, moderate, or severe.
Game Score Calculator
Convert raw game, quiz or test scores to a percentage and US letter grade, with optional penalty deductions and bonus point adjustments.
Gastric Sleeve Weight Loss Calculator
Estimate weight loss outcomes after gastric sleeve surgery based on median EWL% from published clinical research.
Geriatric BMI Calculator
BMI calculator with geriatric-adjusted cut-offs for adults aged 60+. Healthy range shifts to 22–27 to reduce malnutrition risk in older adults.
孕周计算器
根据末次月经 (LMP) 计算你已怀孕几周几天,并显示孕期阶段、预产期和剩余天数。
GFR Calculator
Estimate glomerular filtration rate (eGFR) using the 2021 CKD-EPI race-free formula from serum creatinine, age and sex. Shows KDIGO CKD stage.
GI Calculator
Calculate the Glycemic Load (GL) of a food from its Glycemic Index (GI) and carbohydrate content per serving.
GIR Calculator
Calculate the Glucose Infusion Rate (GIR) in mg/kg/min from dextrose concentration, infusion rate, and patient weight.
Glasgow Coma Scale (GCS) Calculator
Calculate the Glasgow Coma Scale score from eye, verbal, and motor responses to assess level of consciousness.
Glycemic Load Calculator
Calculate the glycemic load (GL) of any food from its Glycemic Index and net carbohydrates per serving to assess blood-sugar impact.
Goalie Save Percentage Calculator
Calculate a goalie's save percentage (SV%) and Goals Against Average (GAA) from shots faced and goals allowed in hockey or soccer.
Gorlin Formula Calculator
Calculate mitral, aortic or tricuspid valve area using the Gorlin formula from cardiac output, heart rate, filling period and mean pressure gradient.
Gout Classification Calculator
Apply the ACR/EULAR 2015 gout classification criteria: score joint pattern, clinical features, serum urate, and imaging to classify gout.
GRACE Score Calculator
Calculate the GRACE score for acute coronary syndrome to estimate in-hospital mortality risk from age, BP, HR, creatinine, Killip class and ECG findings.
Gut Microbiome Score Calculator
Estimate gut microbiome-supportive lifestyle score based on fiber intake, plant variety, fermented foods, antibiotic use and sleep quality.
Half Marathon Pace Calculator
Calculate your half marathon pace per km and per mile, speed, and cumulative split times from a finish time.
Hand Sanitizer Calculator
Calculate doses per bottle, cost per application and supply needs — or get a DIY recipe to dilute alcohol to the WHO-recommended 60–80% concentration.
Happiness Calculator
Estimate your subjective well-being with a PERMA-based composite score across positive emotions, engagement, relationships, meaning, accomplishment and lifestyle factors.
HAS-BLED Score Calculator
Calculate the HAS-BLED score to estimate major bleeding risk in patients with atrial fibrillation receiving anticoagulant therapy.
hCG Levels Calculator
Check if your hCG level is within the typical range for your week of pregnancy. Reference values from published clinical data.
HCT / HGB Calculator
Convert between hematocrit (HCT) and hemoglobin (HGB) using the standard MCHC formula, and check against normal ranges for men and women.
Head Circumference Percentile Calculator (0–24 months)
Calculate a baby or toddler's head circumference percentile using WHO Child Growth Standards for boys and girls aged 0–24 months.
Heart Failure Life Expectancy Calculator
Estimate median survival with heart failure by NYHA functional class, ejection fraction, and age — based on published cohort data.
Heart Rate Recovery Calculator
Calculate heart rate recovery (HRR) after exercise and assess cardiovascular fitness — an abnormal HRR is linked to elevated mortality risk.
心率区间计算器
根据你的年龄以每分钟心跳次数计算你的最大心率和五个训练区间,让有氧锻炼更高效。
HEART Score Calculator
Calculate the HEART score to stratify chest pain patients for Major Adverse Cardiac Events (MACE). For use by healthcare professionals.
Hemoglobin A1c Calculator
Convert HbA1c % to estimated average glucose (eAG) in mg/dL and mmol/L using the ADA formula, with diabetes risk category.
Heptathlon Score Calculator
Calculate a women's heptathlon total score using the official IAAF 1985 scoring tables for all seven events.
Hiking Calories Calculator
Estimate calories burned hiking from body weight, distance, elevation gain, speed and pack weight.
Hiking Time Calculator
Estimate hiking time using Naismith's Rule with Langmuir's descent correction and a fitness-level multiplier.
HOMA-IR Calculator
Calculate HOMA-IR and beta-cell function (HOMA-β) from fasting glucose and fasting insulin to screen for insulin resistance.
HSI Calculator
Calculate the Hepatic Steatosis Index (HSI) from ALT, AST, BMI, sex and diabetes status to screen for non-alcoholic fatty liver disease.
Hull Speed Calculator
Calculate the theoretical hull speed of any displacement vessel from waterline length: results in knots, km/h, and mph with a Froude number.
Human Punch Force Calculator
Estimate punch force in newtons, kgf, and lbf from body weight and fist speed using a biomechanical effective-mass model.
ICC Calculator
Calculate ICC(1,1) or ICC(1,k) from one-way ANOVA mean squares to assess inter-rater or test-retest reliability, plus SEM and MDC₉₅.
ICH Score Calculator
Calculate the validated ICH Score (0–6) from GCS, hemorrhage volume, IVH, location and age to estimate 30-day mortality risk.
ICH Volume Calculator
Estimate intracerebral hemorrhage volume from CT scan measurements using the validated ABC/2 formula. Enter diameters and slice count to get mL volume.
理想体重计算器
使用广泛采用的 Devine 公式,根据你的身高和性别以千克求出你的理想体重,并给出一个健康参考范围。
IIFYM Calculator
Calculate your TDEE-based daily calorie target and flexible macro breakdown (protein, fat, carbs) using the IIFYM method.
Implantation Calculator
Find your implantation window (days 6–12 after ovulation) and see where today falls within it.
Incidence Rate Calculator
Calculate the incidence rate (new cases per 100,000 or any multiplier), incidence proportion and attack rate from case count and population.
INR Calculator
Calculate the International Normalized Ratio (INR) from PT, mean normal PT, and ISI — with therapeutic range interpretation for warfarin monitoring.
IQ Percentile Calculator
Convert any IQ score to a percentile rank and population frequency using the normal distribution (mean 100, SD 15, Wechsler scale).
Iron Deficiency Calculator
Estimate total body iron deficit in mg using the Ganzoni formula: weight × (target Hb − actual Hb) × 2.4 + iron stores.
Isotretinoin Cumulative Dose Calculator
Calculate the cumulative isotretinoin dose (mg/kg) for an acne treatment course and compare it to the 120–150 mg/kg target range.
ISS Calculator
Calculate the Injury Severity Score (ISS) from AIS region scores to classify trauma severity from minor to unsurvivable.
IV Flow Rate Calculator
Calculate IV infusion flow rate in mL/hr and drip rate in drops/min from total volume, infusion time and drop factor.
Jump Rope Calorie Calculator
Estimate calories burned jumping rope by body weight, duration and pace. Uses MET values from the Compendium of Physical Activities.
Karvonen Formula Calculator
Calculate target heart rate and all 5 Karvonen training zones from age, resting HR and target intensity. Uses the Heart Rate Reserve method.
Keto Calculator
Calculate your daily keto calorie target with net carb, protein, and fat goals in grams using the Mifflin-St Jeor BMR formula.
Kidney Stone Calculator
Estimate kidney stone volume and spontaneous passage probability from imaging dimensions (mm).
Kiteboarding Calculator
Find the right kite size for your weight and wind speed, estimate aerodynamic lift force, and calculate calories burned during a kiteboarding session.
Kt/V Calculator
Calculate single-pool Kt/V (Daugirdas second-generation formula) to assess haemodialysis adequacy against the KDOQI ≥ 1.2 target.
LDL Cholesterol Calculator
Estimate LDL cholesterol from Total Cholesterol, HDL and Triglycerides using the Friedewald equation (mg/dL or mmol/L).
瘦体重计算器
使用 Boer 公式,根据体重、身高和性别以千克估算你的瘦体重 (LBM),外加近似脂肪量。
Light's Criteria Calculator
Apply Light's criteria to classify a pleural effusion as exudate or transudate using pleural fluid and serum protein and LDH values.
Lille Score Calculator
Calculate the Lille model score to predict corticosteroid response at day 7 in severe alcoholic hepatitis and guide continuation of therapy.
Local Anesthetic Calculator
Calculate the weight-based maximum safe dose and corresponding volume for local anesthetic agents — lidocaine, bupivacaine, ropivacaine and more.
LRINEC Score Calculator
Calculate the LRINEC score from six routine lab values to assess the probability of necrotizing fasciitis, with instant risk stratification.
Lubricant Cost to Run Calculator
Calculate the annual cost of lubricating a treadmill or exercise machine based on weekly usage, application interval, and lubricant price.
Lung Cancer Risk Calculator for Smokers
Estimate pack-years, check USPSTF LDCT screening eligibility, and see your qualitative lung-cancer risk category as a current or former smoker.
Lung Capacity Calculator
Predict your FVC and FEV1 lung volumes using validated Quanjer 1993 spirometry reference equations for your age, height, and sex.
Lung Nodule Growth Rate Calculator
Calculate the Volume Doubling Time (VDT) of a pulmonary nodule from two CT diameters and the scan interval to assess malignancy risk.
Luteal Phase Calculator
Calculate your luteal phase start, estimated ovulation date, fertile window, and next period date from your cycle length and luteal phase duration.
LV Mass Index Calculator (LVMI)
Calculate Left Ventricular Mass Index (LVMI) from echocardiographic measurements using the ASE Devereux formula and DuBois BSA to detect LV hypertrophy.
Lymphocyte Count Calculator
Calculate absolute lymphocyte count (ALC) from WBC and lymphocyte percentage, with normal range classification.
宏量营养素计算器
为均衡、低碳水或高蛋白饮食配比,将每日热量转换为碳水化合物、蛋白质和脂肪的克数。
Maddrey's Discriminant Function Calculator
Calculate Maddrey's Discriminant Function (MDF) to assess severity and short-term mortality risk in alcoholic hepatitis.
Magic Mile Calculator
Predict your 5K, 10K, half-marathon and marathon finish times from a 1-mile time trial using Jeff Galloway's Magic Mile method.
Magic Number Calculator
Find your personal "magic number" — the days needed to reach a goal weight — from your calorie deficit using the 7,700 kcal/kg fat rule.
Maintenance Calorie Calculator
Find your daily maintenance calories (TDEE) using the Mifflin–St Jeor formula — plus cut and bulk targets.
Maintenance Fluids Calculator for Children
Calculate paediatric maintenance IV fluid rates using the Holliday-Segar method: daily mL and hourly mL/hr by weight.
Marathon Pace Calculator
Calculate the pace per kilometre and per mile needed to finish a marathon in your goal time, with even-effort split projections for 5K, 10K, the half, and the finish.
Mask vs No Mask Calculator
Compare the estimated protection offered by different mask types — cloth, surgical, KN95, N95 — versus wearing no mask.
Max Heart Rate Calculator
Estimate your maximum heart rate by age using Fox (220−age), Tanaka and Gellish formulas, plus all five training zones in bpm.
MCA PSV Calculator
Calculate the MCA-PSV Multiple of Median (MoM) for fetal anemia screening using the Mari 2000 formula. For use with specialist guidance.
mcg to IU Converter
Convert micrograms (mcg) to International Units (IU) for vitamins A, D and E using official FDA conversion factors.
Meal Calorie Calculator
Log food items and their calorie counts to total a meal and compare against your daily calorie target.
Mean Airway Pressure Calculator
Calculate mean airway pressure (MAP) in mechanically ventilated patients from PIP, PEEP, inspiratory time, and respiratory rate.
Mean Arterial Pressure (MAP) Calculator
Calculate mean arterial pressure from systolic and diastolic readings. MAP = DBP + (SBP − DBP) / 3.
Mean Sac Diameter (MSD) Calculator
Calculate mean sac diameter from three ultrasound measurements and estimate gestational age using the MSD + 30 days formula.
Medical Radiation Dose Calculator
Estimate your cumulative effective radiation dose from medical imaging (X-rays, CT scans, PET scans) and compare it to background radiation.
Medicine 3 Times a Day Calculator
Calculate the three best times to take a medication prescribed three times a day (TID), spaced evenly from your first dose.
MELD Score Calculator
Calculate the MELD and MELD-Na score for end-stage liver disease from bilirubin, INR, creatinine and sodium.
Mentzer Index Calculator
Calculate the Mentzer Index (MCV ÷ RBC) to help differentiate thalassemia trait from iron deficiency anaemia in microcytic cases.
MET-Minutes Per Week Calculator
Calculate weekly MET-minutes of physical activity and compare against WHO guidelines. Enter activity, minutes per session, and sessions per week.
Metabolic Syndrome Calculator
Check how many of 5 NCEP ATP III metabolic syndrome criteria are met: abdominal obesity, triglycerides, HDL, blood pressure, and fasting glucose.
Metastatic Prostate Cancer Prognosis Calculator
Apply CHAARTED volume and LATITUDE risk classifications for mHSPC, or score unfavorable prognostic factors for mCRPC — educational reference tool.
MEWS Score Calculator
Calculate the Modified Early Warning Score (MEWS) from five vital signs to detect patient deterioration and trigger timely escalation.
Mica Dust Exposure Calculator
Calculate your 8-hour time-weighted average (TWA) for airborne mica dust and Hazard Quotient against the NIOSH REL of 3 mg/m³.
Micronutrient Calculator
Check whether your daily vitamin or mineral intake meets the RDA and stays below the upper limit — with status and a visual scale.
MIPI Calculator
Calculate the MIPI score for Mantle Cell Lymphoma risk stratification using age, ECOG PS, LDH/ULN and WBC.
Mitral Valve Area Calculator
Calculate mitral valve area (MVA) from Pressure Half-Time using the Hatle formula (MVA = 220 / PHT) with ACC/AHA severity classification.
MME Calculator
Convert any opioid dose to morphine milligram equivalents (MME/day) using CDC 2022 conversion factors.
mmol/L to mg/dL Calculator
Convert blood glucose, cholesterol, triglycerides and other lab values between mmol/L and mg/dL instantly.
Morse Fall Scale Calculator
Calculate the Morse Fall Scale (MFS) score to classify fall risk in hospitalised patients across 6 validated criteria.
Mortality Rate Calculator
Calculate the crude mortality rate per 1 k / 10 k / 100 k population and the case fatality rate from deaths, population, and confirmed cases.
NAFLD Fibrosis Score Calculator
Calculate the NAFLD Fibrosis Score (NFS) to estimate likelihood of advanced liver fibrosis (F3–F4) in non-alcoholic fatty liver disease.
Navy PRT Calculator
Estimate your US Navy Physical Readiness Test (PRT) composite score for push-ups, curl-ups and the 1.5-mile run by age group and gender.
NEDOCS Calculator
Calculate the NEDOCS score to quantify emergency department overcrowding. Enter current ED census data and see the validated 0–200 crowding level.
Net Carbs Calculator
Calculate net carbs by subtracting fiber and sugar alcohols from total carbohydrates. Supports full and half sugar-alcohol deduction methods for keto and low-carb tracking.
Newborn Hyperbilirubinemia Assessment Calculator
Assess neonatal jaundice risk using the Bhutani hour-specific nomogram: enter TSB, postnatal age, and gestational age to identify the risk zone and estimated phototherapy threshold.
NFL Passer Rating Calculator
Calculate the official NFL passer rating (quarterback rating) from completions, attempts, passing yards, touchdowns and interceptions.
NIH Stroke Scale (NIHSS) Calculator
Calculate the NIH Stroke Scale score (0–42) across all 15 items to quantify stroke severity. For clinical reference only.
NLR Calculator
Calculate the Neutrophil-to-Lymphocyte Ratio (NLR) from CBC counts — a rapid blood-test marker for systemic inflammation.
NNT Calculator
Calculate NNT, NNH, ARR, RRR, Relative Risk and Odds Ratio from control and experimental event rates.
Noise Pollution Calculator
Predict sound levels at any distance from a noise source and check WHO community risk and NIOSH occupational exposure limits.
NRR Calculator
Calculate the real-world noise reduction and protected dBA level from a hearing protector's NRR rating, using NIOSH or EPA methods.
Nuchal Translucency (NT) Calculator
Estimate nuchal translucency MoM from NT measurement and CRL, with gestational age and risk category — for educational reference only.
On-Base Percentage Calculator
Calculate OBP, slugging percentage and OPS from hits, walks, at-bats and other batting stats using official MLB formulas.
单次最大重量 (1RM) 计算器
使用 Epley 公式从一组训练估算你的单次最大重量 (1RM),并提供训练负荷百分比表(95%–70%)及对应目标重复区间。
Opioid Conversion Calculator
Convert between opioids using CDC 2022 MME factors and a configurable cross-tolerance reduction (25–50%) for safe opioid rotation.
Osteoporosis Risk Score Calculator (OST Index)
Calculate your OST (Osteoporosis Self-Assessment Tool) index to estimate low bone density risk in postmenopausal women using weight and age.
Overweight Calculator
Check if you are overweight using BMI, see your healthy weight range for your height, and find how much to lose or gain.
排卵计算器
根据末次月经和周期长度估算你的排卵日和易孕期,以及你下次预计来月经的日期。免费的排卵与生育力计算器。
Oxygenation Index (OI) Calculator
Calculate the oxygenation index from MAP, FiO₂, and PaO₂ to assess severity of respiratory failure.
Pace Calculator
Calculate your running or walking pace (min/km or min/mile) from distance and time, with race finish time predictions.
Pack-Years Calculator
Calculate pack-years of smoking history from cigarettes per day and years smoked, with risk category indication.
Padua Score Calculator
Calculate the Padua Prediction Score to assess venous thromboembolism (VTE) risk in acutely ill hospitalised patients.
PaO₂/FiO₂ Ratio Calculator
Calculate the PaO₂/FiO₂ ratio (Horowitz index) from arterial blood gas values and classify ARDS severity using the Berlin 2012 definition.
Parkland Formula Calculator
Calculate IV fluid requirements for burn patients using the Parkland formula (4 mL/kg/%TBSA) or Modified Brooke formula, with first-8-hour and next-16-hour rates.
Peak Flow Calculator
Calculate your predicted peak expiratory flow rate (PEFR) by age, height and sex using the Nunn & Gregg (1989) reference equations, and find your asthma traffic-light zone.
Pearl Index Calculator
Calculate the Pearl Index — the number of unintended pregnancies per 100 woman-years — to measure the effectiveness of a contraceptive method.
PECARN Head CT Decision Rule Calculator
Apply the PECARN pediatric head CT decision rule to stratify children with minor blunt head trauma into Low, Intermediate, or High risk for clinically important brain injury.
Pediatric Blood Pressure Calculator
Compare a child's blood pressure to age- and sex-specific percentile thresholds from the NHLBI 4th Report and AAP 2017 CPG.
Pediatric Blood Volume Calculator
Estimate a child's total blood volume (EBV) from body weight and age group using established mL/kg reference values.
Pediatric Epworth Sleepiness Scale (ESS) Calculator
Score the Epworth Sleepiness Scale (ESS) for adolescents to quantify daytime sleepiness. Scores above 10 suggest excessive daytime sleepiness.
Pediatric GFR Calculator
Estimate the glomerular filtration rate in children using the Bedside Schwartz 2009 or Classic Schwartz formula from height and serum creatinine.
Pediatric Transfusion Calculator
Calculate the packed red blood cell (pRBC) transfusion volume for a child from current and target haemoglobin, body weight, and age group.
PERC Rule Calculator
Apply the 8-item PERC rule to safely exclude pulmonary embolism without D-dimer testing in low pre-test probability patients.
月经计算器
根据你的末次月经和平均周期长度,预测接下来 3 次月经的开始与结束日期,以及预计排卵日。
PG/E2 Ratio Calculator
Calculate the Progesterone-to-Estradiol (PG/E2) ratio from serum levels. Supports ng/mL, nmol/L and pg/mL inputs with luteal-phase interpretation.
PHQ-9 Depression Screening Calculator
Score the PHQ-9 depression questionnaire (0–27) to assess depressive symptom severity from minimal to severe.
PISA Calculator
Calculate EROA and regurgitant volume for mitral regurgitation by the PISA (Proximal Isovelocity Surface Area) echocardiographic method.
Plasma Osmolality Calculator
Calculate serum/plasma osmolality from sodium, glucose and BUN using the Smithline–Gardner formula, with osmol gap.
Plasma Volume Calculator
Estimate plasma volume from height, weight and hematocrit using the Nadler formula for total blood volume.
Pokémon GO Walking Calculator
Track your Pokémon GO egg hatching progress and buddy candy earnings by distance walked. Find how far left to reach your candy goal.
Ponderal Index Calculator
Calculate your Ponderal Index (PI = kg/m³) — a body-weight index that adjusts for height more accurately than BMI for tall or short individuals.
Pool Table Room Size Calculator
Calculate the minimum room size for a pool or snooker table — 7 ft to 12 ft — with full cue clearance on every side.
Positive Pregnancy Test Calculator
Estimate the true probability of pregnancy after a positive home test using test sensitivity, specificity and your prior likelihood (Bayes theorem).
Post-Void Residual (PVR) Calculator
Interpret a post-void residual (PVR) bladder scan — residual fraction, estimated capacity, and clinical severity category.
怀孕计算器
逐周追踪你的怀孕进程。输入末次月经,即可知道你当前的孕周、孕期阶段、预产期以及怀孕进度。
怀孕预产期计算器
根据末次月经和周期长度,使用内格勒法则估算怀孕预产期。查看孕周、孕期阶段和受孕日期。
Pregnancy Test at 3 Weeks Calculator
Understand what "3 weeks pregnant" really means for a pregnancy test, estimate hCG levels, and find out if a test would likely be positive.
Pregnancy Test Calculator
Estimate hCG levels by days past ovulation and see whether a home pregnancy test is likely to be positive or negative.
Pregnancy Weight Gain Calculator
Find your recommended gestational weight gain range by pre-pregnancy BMI, track weekly targets, and see if your current gain is on track — based on IOM 2009 guidelines.
Find your recommended total pregnancy weight gain by pre-pregnancy BMI using IOM 2009 guidelines, with trimester breakdown and weekly rate.
Prescription Refill Calculator
Calculate when your prescription runs out, how many pills you have left today, and the recommended date to request a refill.
Protein-Creatinine Ratio Calculator (Urine PCR)
Calculate the urine protein-to-creatinine ratio (PCR) from a spot sample — estimates 24-hour proteinuria without a timed collection.
PSA Density Calculator
Calculate PSA density (PSAD) from serum PSA and prostate volume — helps distinguish cancer from benign prostatic enlargement.
PSA Doubling Time Calculator (PSADT)
Calculate PSA doubling time from two serial PSA readings — indicates rate of prostate cancer progression and guides treatment decisions.
PSI Calculator
Calculate the Physiological Strain Index (PSI) from core body temperature and heart rate to quantify heat stress during exercise or occupational heat exposure.
Qp:Qs Ratio Calculator
Calculate the pulmonary-to-systemic blood flow ratio (Qp:Qs) from cardiac catheterisation oxygen saturations to quantify intracardiac shunts.
qSOFA Score Calculator
Calculate the quick SOFA (qSOFA) score to screen for sepsis risk at the bedside. Score ≥ 2 warrants urgent evaluation.
QTc Calculator
Calculate the heart-rate-corrected QT interval (QTc) using Bazett, Fridericia, Framingham or Hodges formula — with prolongation risk interpretation.
Quarantine Activity Calculator
Plan home workouts during quarantine: enter days, daily exercise minutes and intensity to see total calories burned and WHO compliance percentage.
QUICKI Calculator
Calculate the Quantitative Insulin Sensitivity Check Index (QUICKI) from fasting insulin and glucose to assess insulin resistance.
Race Predictor Calculator
Predict finishing times at any running distance using Pete Riegel's formula T₂ = T₁ × (D₂/D₁)^1.06 — enter one known race result.
Race Time Improvement Calculator
Enter your current race time and target improvement percentage to find your goal time, time to save, and the new pace required to hit it.
Rate-Pressure Product Calculator
Calculate the Rate-Pressure Product (RPP = HR × SBP) to estimate myocardial oxygen demand and cardiac workload during rest or exercise.
RBC Indices Calculator
Calculate MCV, MCH and MCHC red blood cell indices from hemoglobin, hematocrit and RBC count. Useful for classifying anaemia type.
RCRI Calculator
Estimate peri-operative major adverse cardiac event (MACE) risk using the Revised Cardiac Risk Index (Lee Index, 1999) — 6 binary risk factors.
Relative Fat Mass (RFM) Calculator
Estimate body fat percentage with the Relative Fat Mass formula — a simple height-to-waist ratio method shown to outperform BMI.
REM Sleep Calculator
Estimate how much REM sleep you get each night based on total sleep duration, using 90-minute cycle averages for each sleep stage.
Reticulocyte Count Calculator
Calculate the corrected reticulocyte count (CRC) and reticulocyte production index (RPI) to assess bone marrow response in anemia.
Revised Geneva Score Calculator
Estimate the pre-test probability of pulmonary embolism (PE) using the Revised Geneva Score — 8 clinical variables, no arterial blood gas required.
Revised Trauma Score (RTS) Calculator
Calculate the Revised Trauma Score from GCS, systolic BP and respiratory rate — triage and predict survival probability after major trauma.
RMR Calculator
Calculate your Resting Metabolic Rate (RMR) and TDEE using Mifflin-St Jeor or Katch-McArdle — choose based on whether you know your body fat %.
RSBI Calculator
Calculate the Rapid Shallow Breathing Index (RSBI = f/Vt) to predict weaning readiness from mechanical ventilation. Cut-off: < 105 breaths/min/L.
Running Calorie Calculator
Calculate calories burned running from weight, distance and speed — uses MET values from the Compendium of Physical Activities.
跑步配速计算器
根据距离和完成时间计算你以分钟每千米计的跑步配速、以 km/h 计的速度以及每英里配速。
SAAG Calculator
Calculate the Serum-Ascites Albumin Gradient (SAAG) to differentiate portal hypertension from non-portal causes of ascites.
SAPS II Calculator
Calculate the SAPS II score and predicted ICU mortality from 15 clinical variables, based on the Le Gall 1993 scoring system.
Save Percentage Calculator
Calculate a goalkeeper's save percentage (saves ÷ shots on goal × 100) and see how it rates against professional benchmarks.
SCORAD Calculator
Calculate the SCORAD index for atopic dermatitis (eczema) severity: extent, intensity, and subjective symptoms combined into a 0–103 score.
Scuba Diving Weight Calculator
Estimate the starting ballast weight needed for neutral buoyancy when scuba diving — by body weight, suit, water type and tank.
Sepsis Calculator
Calculate the qSOFA score to screen for sepsis risk: respiratory rate, systolic BP, and mentation. Score ≥ 2 suggests high risk.
Serum Osmolality Calculator
Calculate estimated serum osmolality from sodium, glucose and BUN using the standard clinical formula (2×Na + glucose/18 + BUN/2.8).
Shock Index Calculator
Calculate the Shock Index (heart rate ÷ systolic BP) to screen for haemodynamic instability. Normal SI is 0.5–0.7; values above 1.0 suggest significant shock.
Simple Calorie Intake Calculator
Estimate your daily calorie intake for weight loss, maintenance or gain using the Harris-Benedict BMR formula and your activity level.
Ski Size Calculator
Calculate the right ski length for your height, ability level and skiing style — plus ski pole length.
睡眠计算器
利用 90 分钟睡眠周期找到最佳就寝时间或起床时间。在两个周期之间而非周期中途醒来,会让你更精神、更不昏沉。
Sleep Cycle Calculator
Plan sleep timing for complete cycles using a configurable cycle length — find your ideal bedtime or wake time to avoid mid-cycle wake-ups.
Sleep Debt Calculator
Track your weekly sleep debt by comparing nightly actual sleep to your target — see your deficit, average, and estimated recovery time.
Slugging Percentage Calculator
Calculate baseball slugging percentage (SLG = total bases ÷ at-bats), OBP and OPS. Weights singles, doubles, triples and home runs by base value.
Smoking Recovery Calculator
Track your health recovery after quitting smoking: see which milestones you have reached, money saved, and how close you are to full cardiovascular recovery.
Snap Score Calculator
Estimate your Snapchat Snap Score from daily sending, receiving, and story activity — plus daily screen time for digital-wellness awareness.
Sobriety Calculator
Track how long you have been sober: convert days into weeks, months and years, see money saved, and visualise progress toward your next milestone.
Social Distancing Calculator
Calculate the floor area needed to keep a group socially distanced, equivalent room dimensions, and the maximum safe capacity for any space.
Sodium Change Calculator
Predict the change in serum sodium after any IV fluid using the Adrogue-Madias equation — enter Na, weight, fluid type and volume.
Sodium Correction Calculator
Correct serum sodium for high blood glucose using the Katz (1.6) and Hillier (2.4) formulas to find the true sodium level in hyperglycaemia.
Sodium Correction Rate Calculator
Calculate the IV infusion rate (mL/hr) needed to raise serum sodium safely in hyponatraemia using the Adrogue-Madias equation.
Sodium Deficit Calculator
Calculate the total sodium deficit (mEq) and volume of replacement fluid required to reach a target serum sodium in hyponatraemia.
Sodium in Salt Calculator
Convert between table salt (NaCl) weight and sodium content in mg. See how teaspoons of salt compare to the WHO daily sodium limit of 2000 mg.
SOFA Score Calculator
Calculate the SOFA score to assess organ dysfunction severity in ICU patients across 6 organ systems (0–24 scale).
Sperm Analysis Calculator
Evaluate semen analysis results against WHO 2021 reference values: total count, concentration, motility and morphology.
Splits Calculator
Track your progress toward achieving front or straddle splits: enter your current hip clearance from the floor and weekly improvement to see how close you are and when you'll get there.
Stairs Calorie Calculator
Calculate calories burned climbing stairs by body weight, floors climbed, and pace — based on MET values from the 2011 Compendium of Physical Activities.
Standard Drink Calculator
Calculate the number of standard drinks in any alcoholic beverage from its volume and ABV. Supports Australian, UK and US definitions.
Steps to Calories Calculator
Convert step count to calories burned while walking — based on body weight, step length and distance.
Steps to Km Calculator
Convert steps to kilometres, miles, metres and feet using your step length from a pedometer or fitness tracker.
Steps to Miles Calculator
Convert step count to miles, kilometres and calories burned using a height-based stride length estimate.
Stillbirth Risk Calculator
Estimate relative stillbirth risk from key population-level factors: maternal age, BMI, smoking, diabetes, and prior loss.
STOP-BANG Score Calculator
Screen for obstructive sleep apnea risk with the validated STOP-BANG questionnaire. Score 0–8 with low/intermediate/high risk categories.
Stride Length Calculator
Estimate walking or running stride length from height using De Vito regression constants, or calculate it from total distance and step count.
Stroke Volume Calculator
Calculate stroke volume from end-diastolic and end-systolic volumes (EDV − ESV) or from cardiac output divided by heart rate (CO ÷ HR).
Sugar Intake Calculator
Track your daily added sugar from drinks, snacks, and meals and compare it to the AHA 2023 recommended limit (25 g women, 36 g men, 25 g children).
Swimming Calorie Calculator
Calculate calories burned swimming any stroke — freestyle, breaststroke, butterfly and more — using MET values from the Compendium of Physical Activities.
Swimming Time Calculator
Calculate total swim time from distance, pace per 100 m and pool length — includes wall rest stops and split visualisation.
Swiss Cheese Coronavirus Risk Calculator
Model how stacking multiple imperfect COVID-19 protections (vaccine, mask, ventilation, distancing) reduces combined transmission risk.
T-Score Calculator
Calculate your bone density T-Score from a DXA scan BMD (g/cm²) and get a WHO classification: normal, osteopenia, or osteoporosis.
T:E2 Ratio Calculator
Calculate the Testosterone-to-Estradiol (T:E2) ratio using T in ng/dL and E2 in pg/mL, with a reference range band for adult men.
Target Heart Rate Calculator
Find your target heart rate training zone from age and resting heart rate using the Karvonen Heart Rate Reserve method or simple % of HRmax.
TDEE 计算器
使用 Mifflin-St Jeor 公式,根据你的基础代谢率和活动水平估算每日总能量消耗 (TDEE),并给出减重、维持和增重的卡路里目标。
Tennis Calories Burned Calculator
Calculate calories burned playing tennis — singles, doubles, or practice — based on body weight and session duration.
Tidal Volume Calculator
Calculate tidal volume for mechanical ventilation using ideal body weight (Devine formula) and minute ventilation.
Time of Death Calculator
Estimate time of death from body and ambient temperature using Newton's Law of Cooling. Educational model — not a forensic substitute.
TIMI Risk Score for UA/NSTEMI Calculator
Calculate the TIMI risk score for unstable angina and NSTEMI to estimate 14-day risk of major cardiac events.
TIMI STEMI Risk Score Calculator
Calculate the TIMI Risk Score for STEMI to estimate 30-day mortality in patients receiving fibrinolytic therapy (Morrow et al. JAMA 2000).
Tinetti POMA Fall Risk Calculator
Assess fall risk in older adults using the Tinetti Performance-Oriented Mobility Assessment balance and gait score.
tPA Calculator
Calculate the IV Alteplase (tPA) dose for acute ischemic stroke: total dose, IV bolus, and 60-minute infusion by patient weight.
Training Pace Calculator
Calculate running pace per km and mile, speed, split times, and easy/tempo/interval training paces from any race distance and target time.
Transferrin Calculator
Estimate TIBC from transferrin and calculate transferrin saturation % to help assess iron status. Not a substitute for clinical diagnosis.
Triathlon Calculator
Calculate triathlon finish time, segment splits and calorie burn for sprint, Olympic, 70.3 and Ironman events from your swim, bike and run paces.
Triathlon Target Heart Rate Calculator
Calculate target heart rate zones for triathlon swim, bike and run disciplines using the Karvonen heart-rate-reserve method.
Triathlon Training Calculator
Calculate triathlon race split times and training zone paces (easy + tempo) for swimming, cycling and running from your target race paces.
TTKG Calculator
Calculate the transtubular potassium gradient (TTKG) to assess renal potassium handling and differentiate renal from extrarenal causes of dyskalemia.
Twin Pregnancy Weight Gain Calculator
Calculate recommended total weight gain for a twin pregnancy using IOM 2009 guidelines by pre-pregnancy BMI, with progress tracking by gestational week.
Twinning Calculator
Estimate the probability of conceiving twins based on maternal age, family history, prior twin pregnancies and fertility treatment.
Urine Anion Gap Calculator
Calculate the Urine Anion Gap (UAG = Na⁺ + K⁺ − Cl⁻) and interpret it to help differentiate renal from gastrointestinal causes of metabolic acidosis.
Urine Output Calculator
Calculate urine output rate in mL/kg/hr from collected volume, body weight, and time — with oliguria, normal, and polyuria classification.
Urine Pregnancy Test Calculator
Estimate whether a home urine pregnancy test would be positive based on days past ovulation, implantation timing, and test sensitivity.
URR Calculator
Calculate the Urea Reduction Ratio (URR) from pre- and post-dialysis BUN values to assess haemodialysis adequacy against the KDOQI ≥ 65 % target.
US Vaccine Strategy Calculator
Calculate herd immunity thresholds, required vaccination coverage, and effective reproduction number for any disease using R₀ and vaccine efficacy.
Vaccine Efficacy Calculator
Calculate vaccine efficacy (VE), relative risk, absolute risk reduction and number needed to vaccinate from clinical trial or observational study data.
Vaccine Immunity Calculator
Calculate the herd immunity threshold (HIT) from R₀, the minimum vaccine coverage needed, and whether current vaccination + natural immunity is sufficient to stop an epidemic.
Vaccine Production Calculator
Estimate annual vaccine dose output from bioreactor volume, yield, batch duration, number of bioreactors, and fill-finish efficiency.
Vaccine Queue Calculator
Estimate your place in Australia's 2021 COVID-19 vaccine priority queue based on age, healthcare role, and health conditions.
Estimate your place in Canada's 2021 COVID-19 vaccine priority queue based on age, healthcare role, long-term care status, and health conditions.
Estimate your place in England's 2021 COVID-19 JCVI vaccine priority queue based on age, clinical status, and healthcare role.
Estimate your place in India's 2021 COVID-19 vaccine priority queue based on age, healthcare worker status, and comorbidities.
Estimate your place in Malaysia's 2021 PICK COVID-19 vaccine priority queue based on age, frontline status, comorbidities, and essential worker role.
Vaccine Queue Netherlands Calculator
Estimate how long you would wait for a COVID-19 vaccine in the Netherlands based on your priority group, population and daily vaccination capacity.
Vaccine Queue Northern Ireland Calculator
Estimate your COVID-19 vaccine wait time in Northern Ireland based on your JCVI priority group, population and daily vaccination capacity.
Vaccine Queue Philippines Calculator
Estimate your COVID-19 vaccine wait time in the Philippines based on your A/B priority group, population size and daily vaccination capacity.
Vaccine Queue Scotland Calculator
Estimate your COVID-19 vaccine wait time in Scotland based on your JCVI priority group, population and daily vaccination capacity.
Vaccine Queue South Africa Calculator
Estimate your COVID-19 vaccine wait time in South Africa based on your EVDS phase, population size and daily vaccination capacity.
Vaccine Queue UK Calculator
Estimate your COVID-19 vaccine wait time in the UK based on your JCVI priority group, UK population and daily vaccination capacity.
Vaccine Queue Wales Calculator
Estimate when you would have received your COVID-19 vaccine in Wales based on your 2021 JCVI priority group and the daily rollout rate.
VBAC Risk Score Calculator
Calculate the Flamm-Geiger VBAC admission score (0–10) to estimate the likelihood of a successful vaginal birth after cesarean.
Venous Blood pH Calculator
Calculate venous blood pH from HCO₃⁻ and PvCO₂ using Henderson-Hasselbalch and estimate arterial pH from venous values.
Viral Infection SIR Model Calculator
Model viral epidemic spread with the SIR compartmental model — compute R₀, peak infections and herd immunity threshold.
Vital Capacity Calculator
Estimate predicted vital capacity (FVC) by age, sex and height using ECSC 1993 reference equations; compare your measured result as % of predicted.
Vitamin A Calculator
Convert vitamin A intake from IU to mcg RAE, combine retinol and beta-carotene sources, and compare with the RDA and upper safety limit.
Vitamin Calculator
Look up recommended daily vitamin intakes (RDAs) for vitamins A, C, D, E, K, B6, B12 and folate based on your age and sex.
Vitamin D Calculator
Convert vitamin D between IU and mcg, add estimated sun synthesis, and compare total intake against the RDA (600–800 IU) and upper limit (4,000 IU).
VLDL Calculator
Calculate VLDL cholesterol (Triglycerides ÷ 5) and Friedewald LDL from a standard lipid panel in mg/dL or mmol/L.
VO2 Max Calculator
Estimate VO2 max (mL/kg/min) from the Cooper 12-min run, Rockport 1-mile walk test or resting heart rate method, with ACSM fitness category.
VO₂ Max Calculator for Runners
Estimate your VO₂ max from a Cooper 12-minute run test or a recent race time using the Jack Daniels formula.
VTE Risk in Pregnancy Calculator
Estimate venous thromboembolism (DVT/PE) risk in pregnancy and the postpartum period using RCOG guideline risk factors.
Waist-to-Height Ratio Calculator (WHtR)
Calculate your waist-to-height ratio (WHtR) and see your cardiovascular risk zone — keep it under 0.5 for a healthy range.
腰臀比计算器
计算你的腰臀比 (WHR),并根据世界卫生组织针对男性和女性的阈值查看你的健康风险类别。
Wake-Up Time Calculator
Find the right bedtime (or wake-up time) given your target sleep duration and how long you take to fall asleep.
Walking Calorie Calculator
Calculate calories burned walking from body weight, duration and speed using MET values from the Compendium of Physical Activities.
WAR Calculator
Calculate wound area reduction (WAR%) from initial and current wound dimensions to track healing progress and apply the validated 4-week 40% threshold.
Warsaw Method Calculator
Estimate daily energy and protein requirements for hospital patients using the Warsaw clinical nutrition method (25 kcal/kg × activity × stress factor).
Water Deficit Calculator
Calculate your daily water deficit or surplus by comparing your actual fluid intake with your weight-, activity-, and climate-adjusted recommended intake.
饮水量计算器
根据你的体重和每日运动量估算你每天应该喝多少水,以升、毫升和杯显示。
Weight Gain Calculator
Calculate the daily calories needed to gain weight, your TDEE, weekly gain rate, protein target, and how long it will take to reach your goal.
Weight Loss Calculator
Calculate your daily calorie target for weight loss, TDEE, weekly loss rate, and how long it takes to reach your goal weight.
Weight Loss Percentage Calculator
Calculate what percentage of your starting body weight you have lost, remaining weight to your goal, and progress towards it.
Weight Watchers Points Calculator
Estimate WW SmartPoints and PointsPlus from a food's nutrition label using publicly reverse-engineered formulas.
Weight Week by Week Calculator
Track weight loss or gain week by week: enter your starting, current, and goal weight to see your average weekly rate and how many weeks remain.
Wells PE Score Calculator
Calculate the Wells clinical prediction score for pulmonary embolism risk: low (< 2), moderate (2–6), or high (> 6) with estimated PE probability.
WHIP Calculator
Calculate a baseball pitcher's WHIP (Walks plus Hits per Inning Pitched). Enter walks, hits, and innings pitched to get WHIP and a performance rating.
Wilks Calculator
Calculate your Wilks score to compare powerlifting totals across body weights using the original Wilks formula (pre-2019).
Windsurfing Calculator
Calculate calories burned windsurfing, apparent wind speed and angle, estimated boat speed, and recommended sail size for the conditions.
Winning Percentage Calculator
Calculate winning percentage from wins, losses and ties using the standard formula (W + 0.5×T) / games × 100.
Winter's Formula Calculator
Use Winter's formula to find the expected PCO₂ in metabolic acidosis and determine whether respiratory compensation is appropriate.
World Cup Calorie Calculator
Estimate calories burned during a World Cup football match — watching at home, cheering at the stadium, or playing on the pitch.
12小时制与24小时制时间转换器
在12小时制AM/PM格式与24小时制军用时间格式之间即时转换。
小时与分钟求和
对一组时:分时长求和,并可选地从起始时间推算结束时间。
加减天数计算器
从某个日期加上或减去任意天数,求出结果日期和星期几。免费的日期加减天数计算器。
日期时间加减计算器
从任意日期时间中加减年、月、周、日、时、分、秒。
年龄计算器
计算出生日期与任意日期之间精确的年、月、日年龄。
年龄(年、月、周、日、时)
从任意参考日期查看以年、月、周、日、时和分表示的精确年龄。
工作日计算器
计算两个日期之间的工作日(周一至周五),排除周末。免费的工作日和工作日数统计器。
从日期计算工作日
找出从起始日期起N个工作日之后或之前的日历日期,跳过周末(及可选假日)。
日期倒计时
实时倒计时,显示距任意未来日期时间剩余的天、时、分、秒。
Cron表达式下次执行时间计算器
解析5字段cron表达式,以自然语言描述,并从指定起始日期计算后续几次执行时间。
日期差计算器
以年、月、日、周和总天数计算两个日期之间的精确差值。免费的在线日期间隔计算器。
日期格式转换器
将一个日期转换为多种格式:ISO 8601、美式、欧式、长格式、序数和Unix时间戳。
星期几计算器
查找任意日期是星期几。免费的星期几计算器,显示星期、年内第几天、ISO 周数以及是否为闰年。
年中第几天(序数日期)
查找某日期是一年中的第几天(1-366)以及该年剩余天数。
某月天数
查找任意年月的天数,自动处理闰年2月。
距某日天数计算器
计算从今天到任意未来日期的天数,以及剩余的周数。免费的倒数到某日的计算器。
距下次生日还有多少天
倒计时距您下次生日的天数,并显示您将年满的岁数。
小数小时与HH:MM:SS转换器
将小数小时转换为时:分:秒,或反向转换,适用于薪资和工时追踪。
Unix时间戳转日期转换器
将Unix时间戳转换为UTC或任意固定时区偏移下的可读日期,并提供完整日期时间分解。
Excel序列日期转换器
在Excel/Sheets序列日期数字与日历日期之间互转,支持1900和1904两种日期系统。
ISO 8601时长转换器
将P1Y2M10DT2H30M等ISO 8601时长转换为总秒、分、时和天,或从各组件构建时长字符串。
ISO周日期转换器
在格里历日期与ISO 8601周日期(YYYY-Www-D)之间互转,包含ISO周数和星期几。
ISO 周数转日期
将 ISO 8601 年份和周数转换为该周的精确日历日期。
儒略日数转换器
在格里历日期与天文学儒略日数(JDN)和儒略日期之间进行转换。
闰年计算器
使用格里高利历规则检查任意年份是否为闰年,了解原因,并列出接下来的几个闰年以及二月的天数。
军事时间转换器
即时在24小时军事时间与12小时AM/PM制之间转换。
民国(中华民国)↔ 公历年份换算器
在台湾使用的民国(中华民国)纪年与西方公历年份之间互换——民国年 = 公历年 − 1911。
两个日期之间的分钟数
计算两个日期和时间之间的精确分钟数(以及秒数和小时数)。
月相计算器
查找任意日期的近似月相、光照百分比和月龄。
序数日期转换器
在日历日期与ISO序数日期格式YYYY-DDD(年份加年内日序数)之间转换。
配速、速度与时间计算器
用于跑步、骑行和步行的配速、速度、距离或时间求解器,支持单位换算。
季度与财年查找器
使用自定义财年起始月确定任意日期的日历季度、财政季度和财政年度。
RFC 2822 日期转换器
在RFC 2822/电子邮件头格式(如「Tue, 27 Jun 2026 14:30:00 +0000」)与其他格式之间转换日期。
根据日期确定季节
按半球查找某日期所属的气象/天文季节及其进度。
睡眠时间/就寝时间计算器
根据90分钟睡眠周期和入睡时间,计算理想的就寝时间或起床时间。
日出与日落计算器
使用NOAA太阳公式计算任意地点和日期的日出、日落和白昼长度。
时间前(相对时间)
将过去的日期和时间转换为人性化的相对时间短语,并提供完整分解。
两个时间之间的时长
计算两个时钟时间之间的持续时间,可选跨越午夜。
考勤卡与工时表计算器
添加每日上下班打卡时间和休息时间,获取总工时、加班时间和应得工资。
时间间隔计算器
以小时和分钟计算两个时间之间的时长,包括跨夜时段。免费的时间差计算器。
Time Zone Converter
Convert the time between any two cities or time zones, with a live world globe showing day and night. Pick two cities, enter a time, see the local time in the other.
Unix毫秒转换器
将Unix纪元毫秒转换为人类可读的日期和时间,以及反向转换,精确到秒和毫秒。
Unix 时间戳转换器
将 Unix 时间戳(纪元秒数)转换为人类可读的 UTC 和本地日期,并将任意日期转换回 Unix 时间戳。
UTC到本地时间转换器
使用从-12:00到+14:00的固定UTC偏移量,在UTC时间与任意本地时区之间进行转换。
周数计算器
求出任意日期的 ISO 8601 周数,以及 ISO 周年和星期几。免费的“今天是第几周”计算器。
工作日出现次数计数器
计算两个日期之间(含端点)有多少个周一、周五或任意星期几。
两个日期之间的周数
计算两个日期之间完整周数和剩余天数,以及小数形式的周数总计。
工作时长计算器
根据上班打卡和下班打卡时间减去休息时间,以十进制小时和小时:分钟形式计算工作时长。免费的考勤工时计算器。
0-60 Calculator
Calculate average G-force, distance covered and power from a 0–60 mph time. Works for any car, bike or EV spec sheet.
100 Day Calculator
Find the exact date that is 100 days (or any number of days) from a start date — shows the weekday, month breakdown and week count.
120 Day Calculator
Find the exact date that is 120 days (or any number of days) from a start date — with weekday, week breakdown and calendar-year context.
180 Day Calculator
Find the exact date 180 days from any start date, or 180 days in the past. Useful for visa rules, financial deadlines, and legal timeframes.
30 Day Calculator
Find the exact date that is 30 days (or any number of days) before or after a given start date.
30 Min Calculator
Find the exact time that is 30 minutes (or any number of minutes) before or after a given start time.
3D Printing Cost Calculator
Calculate the cost of a 3D print from filament or resin weight, material price per kg, electricity rate, and expected failure rate.
3D Render Time Calculator
Estimate 3D render time for animations and stills: enter a test-frame benchmark, scale to final sample count and total frames.
45-Day Calculator
Find the date that is exactly 45 days (or any number of days) before or after any start date — shows the weekday and weeks + days breakdown.
6 Month Calculator
Find the exact date that is 6 months before or after any calendar date, plus the difference in days and weeks.
60 Day Calculator
Find the exact date 60 days before or after any calendar date, with the day of the week, weeks and approximate months.
8-Hour Shift Calculator
Calculate when your work shift ends given a start time, paid hours and unpaid break duration — works for any shift length.
90 Day Calculator
Find the date exactly 90 days (or any number of days) from a start date — shows the weekday, month and year of the result.
AC Tonnage Calculator
Calculate the air conditioner tonnage and BTU/hr needed for a room based on area, ceiling height, climate, and occupancy.
Acceptance Rate Calculator
Calculate acceptance rate as a percentage: accepted ÷ applied × 100. Also shows rejection rate and odds against acceptance.
ACT Score Calculator
Calculate your ACT composite score from English, Math, Reading and Science section scores, plus your approximate national percentile.
Adding Hours and Minutes Calculator
Add up to four time durations expressed as hours and minutes — get the total in H h MM min format and as decimal hours.
Adding Hours Calculator
Add (or subtract) any number of hours and minutes to a start time — handles day rollovers and shows the result in 12-hour and 24-hour format.
Age Difference Calculator
Find the exact age difference between two people in years, months and days. Enter any two dates of birth to see the precise gap.
Age in Days Calculator
Find out exactly how many days old you are. Enter your date of birth and a reference date to get the precise day count.
Age in Hours Calculator
Calculate exactly how many hours old you are. Enter your date of birth and a reference date to get the precise hour count.
Age in Minutes Calculator
Calculate the exact number of minutes you have been alive. Enter your date of birth and a reference date to get the total minute count.
Age in Months Calculator
Calculate exactly how many months old you are from any birth date to a reference date.
Age in Seconds Calculator
Find out exactly how many seconds old you are from any birth date to a reference date.
Age in Weeks Calculator
Calculate exactly how many weeks old you are from a birth date to any reference date.
Age in Years Calculator
Calculate your exact age in years as a decimal, plus a full breakdown into years, months, days, weeks, and total days.
Age on Other Planets Calculator
Find out how old you would be on Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune.
Age to Birthday Calculator
Enter an age in years, months, and days to calculate the estimated birth date on any reference date.
AI Job Risk Calculator
Estimate how much AI could automate your job based on task type, routine work %, social interaction and physical dexterity.
Air Changes Per Hour Calculator
Calculate air changes per hour (ACH) for any room. Enter dimensions and airflow rate to see if your ventilation meets ASHRAE guidelines.
Air Conditioner Room Size Calculator
Calculate the AC cooling capacity (BTU/h and tonnage) needed for your room based on area, ceiling height, sun exposure, occupants and kitchen heat.
Alcohol By Volume (ABV) Calculator
Calculate ABV from original and final gravity readings — plus apparent attenuation, calories per serving, and standard drinks.
Alcohol Dilution Calculator
Calculate how much water to add to dilute a spirit or alcohol solution from a higher ABV to a target ABV — using the C₁V₁ = C₂V₂ formula.
Aluminum Weight Calculator
Calculate the weight of aluminum sheet, round rod, square bar, or tube in kg, lb or grams from dimensions and alloy density.
Amdahl's Law Calculator
Calculate the theoretical speedup of a parallel program using Amdahl's Law — enter the parallel fraction and number of processors.
Among Us Calculator
Calculate your impostor probability, kills needed to win, votes for majority eject, and random-eject odds for any Among Us lobby.
Angle Cut Calculator
Calculate the miter saw angle to cut each board for any regular polygon frame or custom corner angle — picture frames, crown molding, and multi-sided projects.
Angle of Depression Calculator
Calculate the angle of depression from observer height and horizontal distance — includes slant distance and slope gradient.
Angle of Impact Calculator
Find the angle at which a projectile hits the ground given launch speed, angle, and height. Includes impact speed, range, and flight time.
Anniversary Calculator
Calculate how long since any event date, find the next anniversary, and see traditional anniversary gift names.
Antipode Calculator
Find the antipode of any location: the point on the exact opposite side of the Earth, given a latitude and longitude.
AP Biology Score Calculator
Estimate your AP Biology exam score (1–5) from your multiple choice and free response raw scores using the College Board weighting.
AP Chemistry Score Calculator
Estimate your AP Chemistry exam score (1–5) from your multiple choice and free response raw scores using the College Board section weighting.
AP Language Score Calculator (AP English Lang & Comp)
Estimate your AP English Language and Composition score (1–5) from your multiple choice and essay raw scores using College Board section weighting.
AP World History Score Calculator
Estimate your AP World History composite score and predicted AP score (1–5) from your MCQ, SAQ, DBQ, and LEQ raw scores.
Appliance Depreciation Calculator
Calculate how much an appliance has depreciated and its current book value using straight-line or declining-balance methods.
Appliance Wattage Calculator
Calculate an appliance's real power (watts), apparent power (VA) and energy use from its voltage, current and power factor.
Aquarium Glass Thickness Calculator
Calculate the minimum glass thickness for a rectangular aquarium based on plate bending theory, tank dimensions and a safety factor.
Aquarium Volume Calculator
Calculate the volume of a rectangular or cylindrical aquarium in litres, including water weight for fresh and saltwater setups.
Arch Calculator
Calculate arc length, radius, included angle and area of a circular arch from span and rise. For doorways, bridges and architectural arches.
ASCII Converter
Convert text to ASCII decimal codes (and hex / binary), or convert ASCII codes back to readable text instantly.
长宽比计算器
计算任意尺寸的长宽比,并求取保持原始比例的缺失宽度或高度。
Asphalt Calculator
Calculate how much asphalt (hot-mix) you need by weight and volume from area length, width and thickness. Supports metric and imperial.
Audio File Size Calculator
Estimate audio file size for WAV, FLAC, MP3, and AAC from duration, sample rate, bit depth and channel count.
Audiobook Speed Calculator
Calculate how long an audiobook takes to finish at any playback speed (0.5× to 4×) and see exactly how much time you save.
Audiobooks Calculator
Find how many audiobooks you can finish per week, month, or year based on daily listening time, book length, and playback speed.
Azimuth Calculator
Calculate the azimuth (compass bearing) and great-circle distance between two geographic coordinates using latitude and longitude.
Baby Age Calculator
Find your baby's exact age in days, weeks, months and years from their date of birth.
Back to School Calculator
Calculate your total back-to-school budget: supplies, clothing, electronics, activity fees, and lunches for one or more children.
Bacon Curing Calculator
Calculate the exact salt, pink curing salt, and sugar amounts for equilibrium-curing a pork belly or other cut, plus minimum fridge curing time.
Bag Weight Calculator
Check if your bag meets airline weight limits. Enter bag weight, the airline allowance and the per-kg excess fee to see total charges.
Baker's Percentage Calculator
Convert baker's percentages into gram weights for any flour amount. Enter hydration, salt, yeast, and other ingredient percentages to get your full recipe.
Balloon Arch Calculator
Calculate how many balloons you need for a balloon arch or garland by entering arch length, balloon size, and style.
Baluster Calculator
Calculate how many balusters (spindles) you need and the exact gap spacing to meet building code requirements for a railing or staircase.
Bandwidth Calculator
Calculate how long a file transfer will take given your connection speed, or find the bandwidth needed to transfer a file in a target time.
Bandwidth-Delay Product Calculator
Calculate the bandwidth-delay product (BDP) to find the minimum TCP window size needed to fully utilise a network link.
Base64 Encoder / Decoder
Encode plain text to Base64 or decode a Base64 string back to text — instantly in your browser, with size overhead stats.
Bath vs Shower Water & Carbon Footprint Calculator
Compare annual water use and CO₂ emissions from baths versus showers. See which habit uses more energy and how to reduce your footprint.
Bathroom Mirror Size Calculator
Find the ideal bathroom mirror width, height and mounting position based on your vanity size and eye height. Includes inches and cm.
Battery Capacity Calculator
Convert battery capacity from mAh to Wh, joules and kWh. Check against the IATA 100 Wh air-travel limit and see current state of charge.
Battery Charge Time Calculator
Calculate how long it takes to charge a battery. Enter capacity (mAh), charger current (mA), starting level and efficiency for an accurate time estimate.
Battery Life Calculator
Calculate how long a battery will last. Enter capacity (mAh) and device current draw (mA) to get runtime in hours and days of use.
Battery Size Calculator
Calculate the battery capacity (mAh) needed to run a device for a target time, or how long a battery will last at a given current draw.
Baud Rate Calculator
Convert baud rate to bits per second, characters per second and file transfer time for UART, RS-232 and modulated RF links.
BBQ Grill Size Calculator
Calculate the BBQ grill cooking area you need for your guest count and food type, with recommended grill size category.
BBQ Party Calculator
Calculate how much meat, burgers, sausages, sides, drinks and ice to buy for a BBQ party based on guests and party length.
BC to AD Calculator
Convert BC (BCE) years to AD (CE), find how many years ago an event happened, and see the century, millennium and timeline position.
Beach Price Index Calculator
Estimate the total cost of a beach day — transport, parking, food, drinks, sunscreen, equipment rental and activities — split by person.
Beam Deflection Calculator
Calculate maximum beam deflection for simply supported or cantilever beams with a central point load or uniform distributed load. Rectangular sections.
Beam Load Calculator
Calculate support reactions (R_A, R_B) and the maximum bending moment for a simply supported beam under a point load or uniform distributed load.
Bean Bag Filling Calculator
Calculate how many litres of EPS beads or shredded foam you need to fill a bean bag chair by entering its diameter and desired fill level.
Beauty Products Calculator
Calculate how many days a beauty or skincare product will last given its volume and your daily usage, plus cost per day.
Bed Size Calculator
Look up standard US and EU bed dimensions, check if a bed fits your room, and see floor coverage and clearance around the bed.
Beer Pong Calculator
Calculate how many cups and how much beer you need for beer pong, including standard drinks per player per game.
Belt Size Calculator
Find your belt size from your waist measurement. Converts between US/UK inch sizing and EU centimetre sizing instantly.
Bending Stress Calculator
Calculate bending stress (σ = M/S) in a rectangular or circular beam cross-section from the applied bending moment, width and height.
Bikini Calculator
Find out how long you can safely stay in the sun without burning, based on UV index, your Fitzpatrick skin type and sunscreen SPF.
账单分摊计算器
将含税费和小费的账单平均分摊给任意人数。
Binary to Text Converter
Decode binary code into readable text — paste space-separated 8-bit bytes or a continuous bit string to get the ASCII output.
Binge-Watching Calculator
Find out how many days it will take to binge a TV show — enter seasons, episodes, episode length and daily hours to watch.
Birdsmouth Cut Calculator
Calculate the seat cut bearing length, pitch angle, and structural check for a birdsmouth notch in roof rafter carpentry.
Birth Year Calculator
Calculate your estimated birth year from your current age and the reference year — with a two-year range to account for whether your birthday has passed.
Birth Year From Death Date Calculator
Calculate the estimated birth year from a year of death and recorded age at death — useful for genealogy, obituaries, and historical research.
Birthday Calculator
Calculate your exact age, total days lived, zodiac sign, the weekday you were born, and how many days remain until your next birthday.
Birthday Countdown Calculator
Count the exact days until your next birthday, see which age you will be turning, track weeks remaining and view your progress through the current birthday year.
Blind Size Calculator
Calculate the correct width and drop for roller, venetian or vertical blinds for inside (recess) or outside (wall) mount — with standard deductions.
Blink-Free Photos Calculator
Find out how many shots to take to get at least one blink-free group photo, based on group size and blink rate.
Board and Batten Calculator
Calculate how many wide boards and narrow battens you need for board-and-batten siding, plus total linear footage with waste factor for any number of walls.
木材板英尺计算器
根据厚度、宽度、长度和数量计算木材的板英尺数及总费用。
Board Foot Calculator
Calculate board feet for a piece of lumber from its thickness, width and length; convert to cubic inches or cubic meters.
Board-on-Board Fence Calculator
Estimate boards, posts and rails for a board-on-board privacy fence from fence length, board width and overlap.
Boat Speed Calculator
Calculate boat speed in knots, km/h and mph from distance and time; also compute theoretical hull speed from waterline length.
Boiler Size Calculator
Estimate the right boiler output (kW) for your home from floor area, insulation level and number of bathrooms.
Bold Text Calculator
Generate Unicode mathematical bold text from any Latin text — copy and paste the bold characters into social media, messaging apps or documents.
Bolt Circle Calculator
Calculate bolt circle (PCD) chord length, arc spacing and hole coordinates for any bolt pattern — for machining, automotive wheels and flange design.
Bolt Torque Calculator
Calculate the tightening torque needed to achieve a target bolt clamping force using the torque-tension formula T = K × F × d, with unit conversions.
Book Challenge Calculator
Track your annual (or any-length) reading challenge: see if you are on pace, how many books you need per week, and your projected total.
Boost Horsepower Calculator
Estimate horsepower gain from a turbocharger or supercharger using boost pressure, base HP and mechanical efficiency.
Bowl Segment Calculator
Calculate the volume, curved surface area and base area of a spherical bowl (spherical cap) from its sphere radius and segment height.
Box Fill Calculator
Calculate how many items fit in a box given box and item dimensions, plus fill percentage and wasted space.
BPM Calculator
Convert BPM to note durations in milliseconds, find the Italian tempo marking, and get beat frequency in Hz for any music tempo.
Bra Size Calculator
Find your UK/US bra size from underbust and overbust measurements in inches or centimetres in seconds.
Bread Spreads Calculator
Calculate how much butter, jam or other spread you need for any number of bread slices, how many jars to buy, and the calorie total.
砖块与砌块计算器
根据墙面面积和砖块尺寸(减去开洞面积)估算所需砖块和砂浆用量。
Brine Calculator
Calculate how much salt to add to water for any brine concentration — perfect for pickling vegetables, lacto-fermentation, and curing.
BSFC Calculator
Calculate Brake-Specific Fuel Consumption (BSFC) from fuel flow rate and brake power to compare engine efficiency.
Butter Calculator
Convert butter between US sticks, cups, tablespoons, teaspoons, grams, ounces, and pounds in one click.
Caesar Cipher Shifter
Encrypt or decrypt text with the Caesar cipher: shift each letter by N positions in the alphabet (ROT13, ROT5, or any shift 0–25).
Cake Pan Converter
Convert cake recipes between different pan sizes and shapes by comparing volumes. Get an exact scale factor to multiply every ingredient by.
Cake Pricing Calculator
Calculate the right selling price for a custom cake by adding ingredient cost, labor, overhead, and a profit markup.
Cake Serving Calculator
Calculate how many slices a round, square, or rectangular cake yields based on pan size and serving size (party, wedding, or generous).
Calendar Calculator
Calculate the number of days between two dates, or add and subtract days from a date. Includes weeks, months, and day-of-week.
Calendar Countdown Calculator
Count the exact days, weeks, hours and minutes between any two dates — deadlines, holidays, birthdays or anniversaries.
卡路里运动换算计算器
计算步行、跑步、骑行或游泳需要多少分钟才能消耗指定的卡路里数。
Camera Field of View Calculator
Calculate horizontal, vertical and diagonal field of view (FOV) in degrees from focal length and sensor size, with crop factor and 35 mm equivalent.
Capital Case Converter
Convert text to Title Case, Capitalized Words, UPPER CASE, lower case, Sentence case, or aLtErNaTiNg case instantly.
Carat Weight Calculator
Convert gemstone carat weight to grams, milligrams, troy ounces and grains, and calculate the total value from a price per carat.
Carbon Equivalent Calculator
Convert any greenhouse gas mass to CO₂ equivalent (CO₂e) using IPCC AR6 100-year global warming potential values.
地毯计算器
根据固定门幅宽度计算所需地毯面积和线米数,含匹配和余料损耗。
Carpooling Calculator
Calculate how much you save each month and year by carpooling — split fuel and parking costs equally among all riders.
CBM Shipping Calculator
Calculate shipment volume in CBM (cubic metres), volumetric weight for air/courier freight, and chargeable weight for any cargo.
吊扇尺寸计算器
根据房间地板面积推荐合适的吊扇叶片直径,并提供吊杆长度建议。
Cement Calculator
Calculate cement bags, sand and aggregate for any volume of concrete. Choose a standard mix grade (M10–M25) or enter a custom ratio to get material quantities instantly.
CFM Calculator
Calculate the required CFM airflow for any room using its dimensions and target air changes per hour (ACH).
Chicken Coop Size Calculator
Calculate the minimum indoor floor area, outdoor run size, nest boxes and roost bar length for your flock.
Child Cost Calculator
Estimate the annual and total cost of raising a child from birth to 18 by income tier, based on the USDA 2017 expenditure report scaled to 2022 dollars.
Chilled Drink Calculator
Calculate how many minutes it takes to chill a drink to your target temperature in a fridge, freezer, or ice bath using Newton's Law of Cooling.
chmod Calculator
Convert octal chmod digits (e.g. 755) to symbolic file permissions (rwxr-xr-x) and see what each bit means.
Chocolate Calculator
Scale any chocolate recipe, calculate calories, fat, carbs and protein for any chocolate type, and find baking substitutions.
Chord Calculator
Calculate the chord length, sagitta, arc length and circular segment area from a circle radius and central angle.
Chord Finder Calculator
Find the notes in any major, minor, 7th, diminished or suspended chord for every root note.
Chord Inversion Calculator
Calculate root position, 1st and 2nd inversions of any triad or 7th chord — see the notes and intervals for every inversion.
Chord Progression Calculator
Generate diatonic chord progressions for any key in major or natural minor — see the chord names for 7 popular patterns.
Chord Transposer Calculator
Transpose a chord progression up or down by any number of semitones, with sharps or flats and slash-chord support.
Christmas Tree Calculator
Estimate how many lights, ornaments, and garland feet your Christmas tree needs based on its height.
Chronological Age Calculator
Calculate your exact age in years, months, and days from your birth date, plus total weeks, days, and hours lived.
CIDR Calculator
Enter an IPv4 CIDR block (e.g. 10.0.0.0/8) to get its network range, host count and how many subnets of a chosen prefix fit inside it.
Circle Skirt Calculator
Calculate the inner radius, outer radius and minimum fabric needed for a full, half or quarter circle skirt with seam allowance.
Classroom Spacing Calculator
Calculate how many desks fit in a classroom with a rectangular grid layout, given room size, desk size, and minimum aisle gap.
Clay Shrinkage Calculator
Calculate how much a clay piece shrinks when drying and firing, or work backwards to find the wet size needed for a target fired dimension.
Cleaning Cost Calculator
Estimate professional cleaning costs from the area, rate per square foot or metre, visit frequency, and any extras — per visit, monthly and annually.
Clearance Hole Calculator
Look up the ISO 273 clearance hole diameter for metric bolts M1.6–M24: choose close, medium, or free fit for your assembly requirement.
Clock Duration Calculator
Calculate the duration between two times of day in hours, minutes and decimal hours. Handles overnight spans automatically.
CM to MM Ring Size Converter
Convert finger circumference from cm to mm and find your EU, US and UK ring size instantly.
CM to Ring Size Converter
Find your ring size from finger circumference in cm. Converts to EU, US, UK letter and Japanese ring sizes instantly.
Coaxial Cable Impedance Calculator
Calculate the characteristic impedance, velocity factor, and capacitance per metre of a coaxial cable from conductor diameters and dielectric material.
Coffee Calculator
Calculate the exact grams of coffee grounds and ml of water for any brewing method — drip, espresso, French press, pour over, AeroPress or cold brew.
Coffee Carbon Footprint Calculator
Estimate the annual CO₂ footprint of your coffee habit — by brewing method and milk choice.
咖啡习惯花费计算器
统计您每日咖啡习惯每周、每月和每年的实际花费。
Coffee Kick Calculator
Find out when your caffeine peaks, when it halves and when it wears off — plan your last coffee for better sleep.
咖啡水比例计算器
为任意冲煮强度或杯数获取克数精确的咖啡与水比例。
抛硬币概率计算器
计算在 n 次抛硬币中恰好、至少或至多出现 k 次正面的概率。
Cold Brew Coffee Ratio Calculator
Find the perfect coffee-to-water ratio for cold brew — concentrate or regular strength — with yield and serving estimates.
College GPA Calculator
Calculate your semester GPA and cumulative GPA on the standard 4.0 scale — enter grades and credit hours for each course.
Commute Calculator
Calculate annual commute time, yearly distance and CO₂ emissions from your daily trip to work.
通勤费用计算器
估算包括燃油、过路费和停车费在内的每日、每月和每年驾车通勤费用。
Compression Ratio Calculator
Calculate engine compression ratio from bore, stroke, and clearance volume. Also shows swept volume and total displacement.
Compression Ratio to PSI Calculator
Convert engine compression ratio to estimated cylinder pressure in PSI, kPa, and bar using the adiabatic compression formula.
Concrete Block Calculator
Estimate how many CMU concrete blocks and how much mortar a wall needs from wall dimensions and opening area. Supports 6", 8" and 12" block sizes.
Concrete Block Fill Calculator
Calculate how much grout or concrete is needed to fill hollow CMU block cores. Supports 6", 8", 10" and 12" blocks with full, alternate or rebar-only fill patterns.
混凝土计算器
根据长度、宽度和厚度(公制或英制单位)估算楼板所需的混凝土。得出以立方码和立方米计的体积,以及 40、60 和 80 磅袋装混凝土的数量。
Concrete Column Calculator
Calculate concrete volume for round or rectangular columns in metric or imperial units. Enter diameter or width/depth, height and count to get yd³, m³ and bag estimates.
Concrete Cylinder Calculator
Calculate concrete volume for cylindrical tube-form footings — fence posts, deck piers and sign-post holes. Metric or imperial; 80, 60 and 40 lb bag counts included.
Concrete Driveway Cost Calculator
Estimate the cost of a concrete driveway from length, width and thickness. Includes material, labor, reinforcement and excavation — all cost rates are editable 2025 estimates.
Concrete Slab Calculator
Calculate concrete volume for a rectangular slab in cubic metres and cubic yards, plus how many 40, 60 or 80 lb bags you need.
Concrete Stairs Calculator
Estimate concrete volume for a straight staircase from step count, rise, run and width, in cubic metres and cubic yards with bag counts.
Concrete Tube / Pier Calculator
Calculate concrete volume for cylindrical tube forms (Sonotubes, piers, footings) from diameter and depth in metric or imperial units.
Concrete Weight Calculator
Calculate the weight of a concrete volume in kilograms, pounds and tonnes. Supports normal, lightweight and heavyweight mixes with a custom density option.
Container Loading Calculator
Calculate how many boxes or cartons fit inside a shipping container or storage space given the container and box dimensions.
Cooking Measurement Calculator
Convert cooking measurements between cups, tablespoons, teaspoons, fluid ounces, pints, quarts, gallons, mL and litres instantly.
Cord of Wood Calculator
Calculate how many cords of firewood are in a pile — enter pile length, height, and log length in feet.
Cost Per Mile Calculator
Calculate the true cost per mile of driving by adding fuel, maintenance, insurance, depreciation and other annual costs, then dividing by miles driven.
Cost Per Minute Calculator
Calculate cost per minute from a total charge and session duration. Useful for phone calls, consultations, streaming, hourly services and any time-based billing.
每份成本计算器
根据总价格和份数计算每份餐食的成本。
每次使用成本计算器
根据价格和使用频率查看任何购买物品的真实每次使用成本。
Count Hours Calculator
Enter hours worked each day of the week to count total hours, overtime, weekday average, and how each day contributes to your weekly total.
Countdown Calculator
Count down days, hours, weeks and minutes to any future date — or count how many days have passed since a past date.
Countersink Depth Calculator
Calculate the countersink depth needed for a flush-head screw given its head diameter, pilot hole diameter and countersink angle (82°, 90° etc.).
Crop Factor Calculator
Calculate the crop factor of any camera sensor and find the equivalent focal length on a 35 mm full-frame camera.
Cross-Stitch Calculator
Calculate the fabric size needed for your cross-stitch project from stitch count, Aida count, and border allowance — plus a thread skein estimate.
Crosstalk Calculator
Calculate crosstalk between audio or signal channels in dB — measure channel separation and determine whether interference is audible.
Crosswind Calculator
Calculate the crosswind and headwind components for any runway from wind speed and direction — essential for pilot go/no-go decisions.
Crushed Stone Calculator
Calculate how much crushed stone or aggregate you need by volume (m³/yd³), weight (tonnes/US tons) and cost for driveways, paths and road bases.
Cubic Yard Calculator
Calculate the volume in cubic yards from length, width and depth in feet. Essential for ordering concrete, mulch, topsoil and gravel.
Cups to Pounds Calculator
Convert cups to pounds for flour, sugar, butter, honey, water and more. Density varies by ingredient — pick yours for an accurate result.
Cursive Font Calculator
Convert any text to Unicode Mathematical Script (cursive) characters for use in social media bios, captions and messages.
Curtain Panel Calculator
Calculate how many curtain panels you need for any window by entering the window width, panel width and desired fullness factor.
Curtain Size Calculator
Calculate the fabric width and drop needed for curtains or drapes from window size, heading style and number of panels.
CV Screening & Interview Time Calculator
Estimate total recruiter time for hiring: CV screening, interview rounds, and candidate pass-through rates.
Cycle Time Calculator
Calculate production cycle time, takt time and throughput rate from available time and units produced — essential for lean manufacturing and process improvement.
D&D 5e Encounter Difficulty Calculator
Calculate D&D 5e encounter difficulty — adjusted XP, Easy / Medium / Hard / Deadly rating and party XP thresholds by level.
D&D Point Buy Calculator
Allocate D&D 5e ability scores using the point-buy system. Shows cost, modifier and points remaining for any 8–15 score array.
Data Usage Calculator
Estimate monthly internet data usage from daily streaming, video calls, music, browsing and gaming hours. See a breakdown by activity.
Date Calculator
Add or subtract any number of days from a date to find a future or past date. Shows the day of week, weeks, and approximate months.
Date of Birth Calculator
Find your exact age in years, months and days, total days and weeks lived, and a countdown to your next birthday.
Date to Date Calculator
Calculate the exact number of days, weeks, months and years between any two calendar dates — forward or backward.
Dating Theory Calculator
Apply optimal stopping theory to dating: find how many candidates to explore before committing for the best mathematical odds of choosing the best match.
Day Countdown Calculator
Count the exact days, weeks, and months until any future date — a simple countdown from any start date to a target event, deadline, or holiday.
Day Counter
Count total days, weekdays, weekend days, and occurrences of each day of the week between any two calendar dates.
Days Between Dates Calculator
Calculate the exact number of days between two dates and get a precise breakdown in years, months, and days — plus total weeks and approximate months.
Days Old Calculator
Find out exactly how many days old you are — plus weeks, hours, and minutes — from any birth date to today.
Deadline Calculator
Calculate calendar days, work days (Mon–Fri) and work hours remaining until a deadline, with a progress bar showing how much time has elapsed.
Decimal Time Conversion Calculator
Convert decimal hours to hours:minutes:seconds and back for payroll, timesheets and project tracking.
甲板板材与搁栅计算器
根据甲板尺寸、板材宽度和搁栅间距估算甲板板材、搁栅和紧固件数量。
Deck Stain Calculator
Calculate how many gallons of deck stain or sealer you need from the deck size, stain type, number of coats and a waste buffer.
Decking Calculator
Estimate how many decking boards you need from the deck size, board width, board length, gap and a waste allowance — imperial or metric.
Delay & Reverb Times Calculator
Calculate tempo-synced delay and reverb pre-delay times in milliseconds for any BPM, including dotted and triplet note values.
Depth of Field Calculator
Calculate the depth of field, near and far focus limits, and hyperfocal distance for any lens, aperture, and sensor format.
Desk Height Calculator
Find the ideal seated or standing desk height, chair seat height and monitor position based on your body height.
Diamond Carat Calculator
Convert diamond carat weight to grams or milligrams, estimate weight from round-cut dimensions, and get a price estimate from price-per-carat.
Diamond Weight Calculator
Estimate a diamond's weight in carats from its length, width and depth — supports round brilliant, princess, oval, pear and other cuts.
Diaper Calculator
Estimate how many diapers your baby needs and the total cost over any period, from a few weeks to a full year.
骰子投掷器(NdM)
投掷任意数量和面数的骰子(NdM),显示每颗骰子的点数及总计。
Dilution Ratio Calculator
Calculate how much concentrate and water to mix for any dilution ratio and desired total volume.
Dimensional Weight Calculator
Find the DIM (volumetric) weight of a parcel and the billable weight that carriers like UPS, FedEx and DHL will charge.
折扣计算器
计算任意折扣百分比下的售价以及你节省的金额。
DIY Shed Cost Calculator
Estimate the material cost to build a DIY shed. Enter dimensions and per-unit material prices to get a cost breakdown by category.
Donut (Torus) Calculator
Calculate the volume and surface area of a torus (donut shape) from major radius R and minor radius r in any length unit.
Door Header Size Calculator
Find the correct door or window header size for a residential framing project using IRC 2021 Table R602.7 for bearing and non-bearing walls.
DPI计算器(打印分辨率)
通过图像像素和尺寸计算打印DPI,或计算清晰打印所需的像素数。
DPMO Calculator
Calculate Defects Per Million Opportunities (DPMO), the Six Sigma sigma level, and process yield for quality analysis.
Drake Equation for Love Calculator
A lighthearted estimate of how many compatible romantic partners live in your area, using a Drake-equation-style filter chain.
Dress Size Calculator
Find your dress size in US, EU and UK sizing from your bust, waist and hip measurements in inches or centimetres.
Drive Time Calculator
Estimate your car trip travel time from distance and average speed, with optional stop time, in km or miles.
Drone Flight Time Calculator
Estimate how long your drone will fly from battery capacity (mAh), average current draw (A) and usable capacity percentage.
Drone Motor Calculator
Estimate static thrust, electrical power, and current draw for a drone motor and propeller combination.
Dry to Cooked Pasta Calculator
Convert dry pasta weight to cooked weight for spaghetti, penne, fusilli and more. Estimates water absorbed and cooked weight per serving.
Drywall Calculator
Estimate drywall sheets, screws, tape and joint compound for a room in feet. Deducts doors and windows; includes 10% waste and an optional material cost.
石膏板计算器
根据墙面和天花板面积计算房间所需的石膏板、螺钉、接缝填料和纸带数量。
Duty Cycle Calculator
Calculate duty cycle, frequency, period, ON/OFF time and average voltage for PWM signals — three input modes.
Earthquake Calculator
Convert Richter/Mw magnitude to energy in joules and compare two earthquakes by amplitude and energy ratio.
Easter Calculator
Find the exact date of Easter Sunday for any year from 1583 to 9999 using the Meeus/Jones/Butcher Gregorian algorithm.
eDPI Calculator
Calculate your effective DPI (eDPI) by multiplying mouse DPI × in-game sensitivity, and find your cm/360° rotation distance.
Egg Boiling Time Calculator
Calculate exactly how long to boil an egg to soft, medium or hard based on egg size, starting temperature and water temperature using a physics heat-conduction formula.
Elapsed Time Calculator
Calculate hours, minutes and exact decimal hours elapsed between any two clock times, including overnight or multi-day spans.
电费计算器
根据功率、每天使用小时数、天数和你的每千瓦时电价,计算电器以 kWh 计的耗电量及其运行成本。
Electricity Cost Calculator
Calculate your electricity bill from kWh consumed, unit rate, daily standing charge and VAT — with an annual cost estimate.
Electricity Cost Single Usage Calculator
Find the electricity cost of one single use of any appliance from its wattage, usage duration and your per-kWh electricity rate.
Elevation Grade Calculator
Calculate road or trail elevation grade as a percentage, plus the angle in degrees and slope ratio from rise and horizontal run.
Email vs Phone Call Calculator
Find how many hours per week you spend on back-and-forth email threads and how much time a quick call would save.
End Portal Finder
Triangulate the Minecraft stronghold / End Portal coordinates from two Eye of Ender throw angles using line-intersection geometry.
Engagement Rate Calculator
Calculate social media engagement rate from likes, comments, shares and saves vs followers — with good/excellent benchmarks per platform.
Engine Hours to Miles Converter
Convert engine hours to estimated miles driven using average operating speed — for cars, trucks, tractors, heavy equipment, and marine engines.
English Learning Calculator
Estimate how many weeks it takes to reach your target CEFR English level based on your current level and weekly study hours.
Epoxy Resin Calculator
Calculate how much epoxy resin and hardener to mix for any casting or tabletop project — enter mold dimensions, mix ratio and a waste allowance.
EU to US Shoe Size Calculator
Convert shoe sizes between EU, US and UK systems for men and women — includes approximate foot length in cm and inches.
EUI Calculator
Calculate a building's Energy Use Intensity (EUI) in kBtu/sq ft/yr or kWh/m²/yr from annual electricity and gas use, with ENERGY STAR benchmark comparison.
Even Parity Calculator
Find the even and odd parity bits for any binary word — count 1-bits, check current parity and generate the error-detection check bit.
Every Second Calculator
Convert any repeating interval — every 5 minutes, every 3 days, every year — into events per second, minute, hour, day and year.
Expiration Date Calculator
Calculate when an item expires from its start date and shelf life, and see how many days are left or how long it has been past expiry.
Exposure Calculator
Calculate the Exposure Value (EV) for any combination of aperture, shutter speed and ISO, and see what lighting conditions your settings suit.
Fabric Calculator
Calculate how many yards or metres of fabric you need for any sewing or quilting project. Includes seam allowance, waste factor and bolt-width layout.
Fence Cost Calculator
Estimate the total cost of a fence project: materials, posts, gates and labor. Covers wood, vinyl, chain-link and aluminum.
Fence Cost Estimate Calculator
Estimate fencing project total cost from dimensions and unit prices — posts, panels, rails, concrete, labor and contingency.
Fence Material Calculator
Calculate fence material quantities: post, rail and picket lineal meters plus concrete bags needed, with a waste factor.
Fence Perimeter Calculator
Calculate total fencing run from plot dimensions: choose how many sides to fence, subtract gate openings and get the linear meters needed.
Fence Picket Calculator
Calculate the number of fence pickets needed from run length, picket width and gap — plus lineal meters, board feet and privacy coverage.
围栏立柱与板材计算器
根据总长度和间距计算一段围栏所需的立柱、板材、横档和竖板。
Fence Post Depth Calculator
Calculate fence post burial depth from fence height and frost line, plus total post length and concrete bags needed per hole.
Film Exposure Calculator
Calculate the Exposure Value (EV) from your aperture, shutter speed and ISO — instantly see how your camera settings map to scene brightness.
期末成绩计算器
根据你目前的成绩和考试权重,准确算出你在期末考试中需要取得多少分才能达到目标成绩。
Fire Flow Calculator
Calculate the needed fire flow (NFF) in gallons per minute for a structure using the Iowa State University formula: NFF = 18 × C × √A.
Fire Glass Calculator
Calculate how many pounds (or kg) of decorative fire glass you need to fill a gas fire pit or fireplace. Supports rectangle and round pits, inches or centimetres.
柴火捆计算器
通过长、宽、高将堆叠木垛转换为捆和面捆,并检查每捆价格。
Flag Calculator
Calculate flag height, area, diagonal and perimeter from the width and aspect ratio — useful for ordering fabric or making flags to correct proportions.
Flight Radiation Calculator
Estimate the cosmic radiation dose received during a flight from altitude, duration and route latitude; compare to X-rays and annual limits.
Floor Area Ratio Calculator
Calculate the Floor Area Ratio (FAR) and plot coverage for a building: total floor area divided by lot area — the core urban-planning density measure.
Floor Joist Calculator
Calculate the number of floor joists, total linear feet, board feet, and material cost for any rectangular floor frame.
Flooring Calculator
Calculate flooring needed for any room — sq ft with waste, number of boxes, and total material cost for tile, laminate, or hardwood.
Focal Length Calculator
Solve the thin-lens equation (1/f = 1/dₒ + 1/dᵢ) for focal length, object distance or image distance, with magnification and image type.
Frames to Timecode Calculator
Convert a frame number to SMPTE timecode (HH:MM:SS:FF) at any frame rate: 24, 25, 29.97, 30, 50, 60 fps.
Framing Calculator
Estimate the number of studs, plates, and total linear feet of lumber for a stud wall at 16" or 24" OC spacing.
Freight Class Calculator
Find the NMFC freight class (50–500) from shipment weight and dimensions — density (PCF) determines the LTL rate.
French Drain Calculator
Calculate gravel volume, weight and pipe flow capacity for a French drain trench using Manning's equation.
Fresh to Dry Herb Conversion Calculator
Convert fresh herbs to dried (or vice versa) using the standard 3:1 ratio. Supports tsp, tbsp, cups, mL and grams.
Fret Calculator
Calculate the exact nut-to-fret distance for any fret on a guitar, bass or other fretted instrument from the scale length.
Fuel Consumption Calculator
Calculate real-world fuel consumption from actual trip distance and fuel used. Get L/100km, km/L, US MPG, UK MPG and a CO₂ estimate in one click.
燃油费用计算器
根据距离、车辆效率和油价估算任何行程的燃油费用,并给出所需升数和每千米成本。
Fuel Distance Calculator
Calculate how far you can drive on the fuel in your tank. Enter litres available and fuel efficiency (km/L) to get your range.
Fuel Mileage Calculator
Calculate your vehicle's fuel mileage from a trip. Enter distance driven and fuel used to get km/L, L/100 km and US mpg.
Fuel Pump Calculator
Calculate how many litres of fuel you can pump for a given budget, or how much a target fill-up will cost at the current pump price.
Furnace Size Calculator
Estimate the furnace size (BTU/hr) you need based on floor area, climate zone, ceiling height, insulation and AFUE efficiency.
Gallons Per Minute Calculator
Calculate water or liquid flow rate in GPM from a measured volume and the time taken to deliver it. Convert to LPM, GPH and LPH.
Gallons Per Square Foot Calculator
Calculate how many US gallons cover each square foot of an area — for irrigation, rainfall, fertilizer or liquid application rates.
Gambrel Roof Calculator
Calculate gambrel (barn) roof area, roofing squares and shingle bundles from building length, width and two-slope pitch design.
Garbage Bag Size Calculator
Find the correct garbage bag size for your trash can — enter can diameter and height (round) or width, depth and height (rectangular) to get the right gallon size and liner dimensions.
Garlic Converter
Convert garlic between cloves, minced teaspoons, tablespoons, garlic powder, and granulated garlic instantly.
Gas Calculator
Calculate gas cost for any trip from distance, MPG or L/100 km, and fuel price — plus fuel needed and CO₂ emissions.
Gas vs Electric Dryer Calculator
Compare the annual running cost of a gas dryer vs an electric dryer based on your local energy prices and usage.
发电机功率计算器
通过汇总所需电器的运行瓦数和启动瓦数,为备用发电机选型。
礼物预算计算器
将节日或活动礼物预算公平地分配给名单上的每个人。
Glass Weight Calculator
Calculate the weight of a flat glass pane from its length, width, thickness and glass type (soda-lime, tempered, borosilicate, lead crystal).
Glitch Text Calculator
Generate glitch (Zalgo) text by stacking Unicode combining diacritical marks above and below each character. Adjust intensity and direction.
Glove Size Calculator
Find your glove size from hand circumference. Converts to US (inches), EU (cm) and letter sizes (XS–2XL) for work gloves, latex gloves and fashion gloves.
Gothic Font Generator
Convert any text to Gothic Fraktur Unicode characters (𝔞𝔟𝔠…) for use in social media bios, headings and creative text.
GPA 计算器
根据每门课程的绩点和学分时数计算你的平均绩点——在几秒内得出快速、准确的加权 GPA。
GPA Calculator Pakistan
Calculate your Pakistani university CGPA from percentage marks using the HEC-recommended 4.0 grading scale.
Grade Calculator
Calculate your weighted average grade from up to five assignments or exams. Enter each score and its percentage weight to get the final grade and letter grade instantly.
Grade Curve Calculator
Calculate your curved grade using four methods: square root curve, flat addition, scale to top score, or mean shift — and see the curve on a chart.
Graduation Year by Birthday Calculator
Find the K–12 graduation year for any birthday using your state's kindergarten enrollment cutoff date.
Graduation Year Calculator
Find your high school graduation year and key school milestones from your current grade level and the current school year.
Grams to Cups Calculator
Convert grams to US cups for flour, sugar, butter, oats, honey and 18 other baking ingredients — with tablespoon and teaspoon equivalents.
Grams to Tablespoons Calculator
Convert grams to US tablespoons for flour, sugar, butter, honey and more — density applied automatically per ingredient.
Grams to Teaspoons Calculator
Convert grams to US teaspoons for salt, baking soda, spices, honey, flour and more — density applied automatically per ingredient.
草籽计算器
根据面积和推荐播种率计算新草坪或补种所需购买的草籽数量。
砾石计算器
根据长度、宽度和深度计算你需要多少砾石或骨料——得出以 m³ 和 yd³ 计的体积、以公吨和美吨计的重量,以及成本。
Gravel Driveway Calculator
Calculate how much gravel you need for a driveway or path: volume in m³ and yd³, weight in tonnes and kg, with an optional cost estimate.
Grocery Calculator
Calculate your grocery total from a shopping list with quantities, add sales tax, and compare to a budget in one step.
Ground Sample Distance (GSD) Calculator
Calculate the GSD for drone or aerial photography — the real-world size of one image pixel based on altitude, focal length and sensor pixel pitch.
Grout Calculator
Calculate how much grout you need for any tiled surface. Enter tile size, joint width, grout depth, and total area to get kg and bag counts with a waste allowance.
商品及服务税 (GST) 计算器
按 5%、12%、18% 或 28% 加上或扣除 GST,并即时显示净额、所收 GST 和含税总额。
Guitar String Tension Calculator
Calculate the tension on a plain guitar or bass string from its diameter, scale length, target pitch frequency and material.
GVWR Calculator
Check whether your vehicle is within its Gross Vehicle Weight Rating. Enter GVWR, curb weight, cargo and passengers to see remaining payload capacity and load percentage.
GWA Calculator
Calculate your GWA (General Weighted Average) for the Philippine academic system. Enter up to five subject grades (1.0–5.0 scale) and credit units to get your weighted average and honor standing.
GWAM Calculator
Calculate GWAM (Gross Words A Minute) and NWAM (Net WPM) from keystrokes, test time and errors — with a speed-tier benchmark.
Hair Growth Calculator
Calculate how many months it takes to grow hair to a target length from a current length, given your personal monthly growth rate.
Half Birthday Calculator
Find the exact half-birthday 6 calendar months from any date of birth, plus the next annual occurrence.
Half-Square Triangle Calculator
Calculate the cut square size for half-square triangles in quilting: finished size + 7⁄8 inch, plus total squares and pairs needed.
Ham Cooking Calculator
Calculate how long to cook a ham by weight and type — fresh, fully cooked, or country ham — at 325°F / 163°C.
Hamming Code Calculator
Calculate the number of parity bits, total codeword length and efficiency for a Hamming SEC or SEC-DED error-correcting code.
Hammock Hang Calculator
Calculate hammock strap length, sag depth and suspension tension from anchor distance, sag angle and occupant weight.
Harmonic Series Calculator
Calculate the partial sum of the harmonic series 1 + 1/2 + 1/3 + … + 1/n and find how many terms are needed to exceed any target value.
Hash Identifier
Paste any hash string and instantly identify the likely algorithm: MD5, SHA-256, bcrypt, SHA-512 and 15+ more.
Hat Size Calculator
Convert head circumference to hat size in US, EU, UK and Japan systems. Enter cm or inches for instant results.
Headphone Power Calculator
Calculate how much power and voltage your amplifier or phone needs to drive headphones to a target listening level, given sensitivity and impedance.
Healthy Coffee Calculator
Find out how much caffeine your daily coffee habit delivers and whether it stays within the safe limit for your health profile.
Heat Loss Calculator
Calculate steady-state heat loss through a wall, window or roof using U-value, area and indoor–outdoor temperature difference, plus annual energy cost.
Helium Balloons Calculator
Find how many helium balloons are needed to lift any object. Uses Archimedes buoyancy, balloon volume and shell weight.
Hex to Text Converter
Convert hexadecimal bytes to readable text (UTF-8) or encode any text string into hex — with byte count and per-byte breakdown.
Hexagon Quilt Calculator
Calculate how many hexagon pieces you need for a quilt and how much fabric to buy — enter quilt size, hexagon side and seam allowance.
High School GPA Calculator
Calculate your weighted high school GPA on the standard 4.0 scale from up to 6 courses with letter grades and credit hours.
Hire an Expert vs Train a Fresher Calculator
Compare the total cost of hiring an experienced professional versus recruiting and training a junior employee over a multi-year period.
Hit Points Calculator
Calculate D&D 5th Edition hit points: select your class hit die, character level, and Constitution modifier to see average, maximum and minimum HP.
Hole Volume Calculator
Calculate the volume of a cylindrical or rectangular hole (fence post, planting pit, trench) plus wall area and total inner surface for lining or cement estimates.
Hoop House Calculator
Calculate the number of hoops, total pipe length, and plastic cover area for a semicircular hoop house greenhouse.
Horsepower Calculator
Calculate horsepower from torque and RPM using HP = Torque × RPM ÷ 5252. Also converts to kW, metric HP (PS/CV), and watts.
Hot Tub Cost Calculator
Estimate your hot tub monthly and annual running costs: electricity, water treatments, and refills in one place.
Hour Countdown Calculator
Convert a countdown in hours into days, hours and minutes remaining — plus track progress if some time has already elapsed.
Hours Calculator
Calculate hours and minutes between a start time and an end time, with optional break deduction — gives decimal hours and H h MM min format.
How Many Tables Calculator
Calculate how many tables you need for a party or event based on guest count, seats per table and an optional head table.
How Much Ham Per Person Calculator
Calculate how many pounds of ham you need per person for a dinner, side dish or party — boneless or bone-in, with an optional buffer.
How Old Am I Calculator
Find your exact age in years, months, days, weeks and total days — plus the countdown to your next birthday.
How Old Was I Calculator
Find out exactly how old you were on any past date — in years, months, days, total weeks and total days.
Humans vs Vampires Calculator
A fun exponential-growth model: how many years until vampires outnumber humans, given a starting count, bite rate, and human growth rate?
Hyperfocal Distance Calculator
Find the hyperfocal distance for any lens and aperture — maximise sharpness from H/2 to infinity for landscape photography.
Ice Cream Calculator
Calculate total scoops, cost and flavor quantities needed for a party or event. Enter guests, scoops per person, price and optional cone and topping costs.
IELTS Score Calculator
Calculate your IELTS overall band score from Listening, Reading, Writing, and Speaking sub-scores using the official rounding method.
Image File Size Calculator
Calculate the uncompressed size of an image from its pixel dimensions and color depth, with estimated PNG and JPEG file sizes.
Image Ratio Calculator
Find the simplified aspect ratio of any image (e.g. 16:9), convert between pixel dimensions while preserving the ratio, and see total megapixels.
Impact Factor Calculator
Calculate a journal's impact factor from citation counts and article numbers for the two prior publication years.
Impedance Matching Calculator
Calculate transformer turns ratio, reflection coefficient, VSWR, return loss and power efficiency for matching source to load impedance.
Inches to Ring Size Converter
Convert a finger measurement in inches to US, EU, UK and Japanese ring sizes. Enter circumference or diameter.
Insulation Calculator
Calculate the R-value, U-value and steady-state heat loss for any insulation material, thickness and area.
IP Address Converter
Convert any IPv4 address to 32-bit binary, hexadecimal, octal and unsigned integer, and look up its class and address type.
IP地址与整数转换器
将IPv4地址转换为32位十进制整数(及十六进制/二进制),或将整数转换回点分十进制格式。
IP Subnet Calculator
Calculate network address, broadcast, subnet mask, host range and usable hosts for any IPv4 CIDR block — enter an IP address and prefix length.
Italic Text Generator
Convert any text to Unicode italic or bold italic characters for social media bios, posts and messages.
Jacket Size Calculator
Find your jacket or suit size in US, UK, EU, Italian and French sizing from your chest measurement and sleeve length.
Jeans Size Calculator
Convert waist and inseam measurements to jeans sizes in US W×L, EU, and UK formats for men and women.
Junction Box Sizing Calculator
Calculate the minimum junction box fill volume required by NEC 314.16(B) for any combination of conductors, grounds, devices and cable clamps.
K-Factor Calculator
Calculate sheet metal bend allowance, bend deduction and flat blank length from material thickness, inside radius, bend angle and K-factor.
K/D Calculator
Calculate your Kill/Death (K/D) ratio, KDA ratio and win rate — for any FPS, battle royale or MOBA game.
Key Signature Calculator
Identify the major and relative minor key for any key signature with 0–7 sharps or flats, and see which notes are affected.
Keystrokes Per Hour Calculator
Convert words per minute (WPM) to keystrokes per hour (KPH) and see where your typing speed ranks among typists.
Korean Age Calculator
Calculate your traditional Korean age (세, se) — born at 1, +1 each January 1 — alongside your international and calendar-year age.
Ladder Angle Calculator
Calculate the angle of a ladder against a wall plus required length. Checks the safe 70–78° placement range.
强化木地板与实木地板计算器
估算房间所需的强化地板或实木地板包数和地板条数,包含切割损耗余量。
Latitude Longitude Distance Calculator
Calculate the great-circle distance between two GPS coordinates in km, miles and nautical miles using the haversine formula.
草坪施肥计算器
根据袋装标注的NPK百分比,计算达到目标含氮量所需施用的肥料用量。
Lead Time Calculator
Calculate total lead time by summing order processing, manufacturing, transit and receiving stages — in days and weeks.
LED Savings Calculator
Calculate annual electricity savings, payback period, and 10-year net savings from replacing incandescent or halogen bulbs with LEDs.
Lens Magnification Calculator
Calculate magnification, image distance, and image type for a thin lens from focal length and object distance.
Letters to Numbers Calculator
Convert any word or phrase to its A=1 B=2 … Z=26 number values, plus the sum, average, and frequency of each letter.
Lighting Calculator
Calculate how many lumens and light bulbs (or LED fixtures) a room needs based on its size and recommended illuminance level.
Limestone Calculator
Calculate cubic yards, tons, and 50 lb bag count of crushed limestone or agricultural lime for any area and depth.
Linear Inches Calculator
Add length + width + height to get linear inches — compare your bag or box against typical airline carry-on and checked-luggage size limits.
Liters per Minute Calculator (L/min)
Calculate flow rate in liters per minute — or solve for volume or time. Converts to L/s, m³/h, and GPM instantly.
LM317 Calculator
Calculate the LM317 output voltage from R1 and R2, or find R2 for a target output voltage — with minimum input voltage and power dissipation.
Local Sidereal Time Calculator
Calculate Local Sidereal Time (LST) and Greenwich Mean Sidereal Time (GMST) for any date, UTC time and geographic longitude.
Log Weight Calculator
Estimate the weight of a round wood log by diameter, length and species — useful for firewood, timber transport and forestry.
Logic Gate Calculator
Compute the binary output of any standard logic gate for given inputs and see the full truth table — AND, OR, NOT, NAND, NOR, XOR, XNOR.
Lord of the Rings Calculator
Find out how many days it would take YOU to walk Frodo's journey from the Shire to Mount Doom based on your walking pace.
彩票号码生成器
随机抽取彩票号码(如49选6),不重复,并带有可选的奖励球。
Louise Glück Poetry Calculator
Analyse any poem's line count, syllables, lexical diversity and reading time, and score how closely it matches Louise Glück's spare minimalist style.
Lumber Calculator
Calculate how many lumber boards you need for a deck, floor, or wall project, with a waste allowance and total cost estimate.
Lumber Weight Calculator
Calculate the weight of lumber boards in lbs and kg for 14 wood species, using actual board dimensions and air-dried wood density.
Lumens to Watts Calculator
Convert lumens (brightness) to watts for LED, CFL, halogen, and incandescent bulbs, and see the energy and cost savings of switching.
Lunar Age Calculator
Calculate your age in lunar months and lunar years based on the synodic month (29.53 days), plus your traditional Chinese lunar age approximation.
Mashed Potatoes Calculator
Find out how many potatoes, how much butter and milk to buy for any number of servings of mashed potatoes.
Mask Supply Calculator
Calculate how many masks a household or team needs for a set number of days, and compare filtration efficiency by mask type.
Matched Betting Calculator
Calculate the lay stake and guaranteed profit for matched betting — qualifier bets and free-bet (SNR) conversions at any exchange commission.
Material Removal Rate Calculator (MRR)
Calculate the material removal rate (MRR) for milling, turning or drilling — width × depth × feed rate — and estimate machining time for a given stock volume.
Mayan Calendar Calculator
Convert any Gregorian date to the Mayan Long Count, Tzolk'in sacred calendar, and Haab solar calendar using the standard GMT correlation.
Meeting Cost Calculator
Calculate the real cost of a meeting in salary time: attendees × hourly rate × duration, plus weekly and annual totals.
Metal Roof Cost Calculator
Estimate the cost of a metal roof from your home's footprint area, pitch, metal type, and per-sq-ft material and labour rates (US 2024 estimates).
Metal Weight Calculator
Calculate the weight of metal plates, round bars, square bars, hex bars, round tubes and square hollow sections in kg and lb from dimensions.
Microwave Wattage Calculator
Adjust microwave cooking time for your wattage. Recipe says 1100 W but you have 700 W? Get the corrected time instantly.
Miles Per Year Calculator
Estimate your total annual mileage from daily commute, weekly errands and vacation driving to budget fuel costs and track vehicle wear.
Miles to Dollars Calculator
Convert frequent flyer miles or reward points to their dollar value using 2025 program valuations.
Minecraft Circle Calculator
Calculate how many blocks you need for a Minecraft circle or disc — ring perimeter blocks and total filled-disc blocks for any diameter.
Minecraft Stack Calculator
Calculate how many Minecraft stacks and inventory slots you need for any number of items, including partial stacks and double chests.
Minute Calculator
Convert any number of minutes to hours, seconds, days and weeks — and see the result in H h MM min format for timesheets and scheduling.
Mirror Text Converter
Flip and reverse any text into upside-down mirror writing using Unicode character substitution — copy and paste anywhere.
Miter Angle Calculator
Calculate the miter cut angle for any corner joint or regular polygon frame — for woodworking, picture frames and trim.
mL to Grams Calculator
Convert millilitres to grams for water, flour, sugar, butter, honey, oil and more. Uses substance density — 1 mL of water = 1 g, 1 mL of flour ≈ 0.53 g.
MM to Carat Conversion Calculator
Estimate the carat weight of a round brilliant diamond from its diameter and depth in millimeters using the standard gemological formula.
MM to Ring Size Converter
Convert finger circumference or inner diameter in mm to US, EU/ISO, UK, and Japanese ring sizes instantly.
Molecular SO₂ Calculator
Calculate the antimicrobially active molecular SO₂ in wine from free SO₂ and pH, and find the free SO₂ needed to hit a target.
Money Weight Calculator
Find how much any dollar amount weighs in grams, kilograms, pounds and ounces — for US bills and coins.
Month Counter
Count the exact number of complete months between any two dates, plus the total in years, weeks and days.
Months Between Dates Calculator
Calculate the exact number of complete months between any two dates, plus the leftover days, total calendar days, and total weeks.
Morse Code Translator
Convert text to Morse code instantly. Supports A–Z, 0–9 and common punctuation marks.
砂浆与填缝剂计算器
根据面积、瓷砖尺寸和接缝宽度估算贴砖工程所需的薄型砂浆和填缝剂。
Mortar Calculator
Calculate how much cement, sand and water you need for a masonry mortar mix from area, joint depth and mix ratio.
MPG Calculator
Calculate miles per gallon (MPG) or L/100 km fuel economy, plus trip cost and cost per mile from distance and fuel used.
护根物计算器
通过花坛长、宽和深度查找所需的立方码或袋装护根物数量,含袋数和体积。
Music Duration Calculator
Calculate total playlist or setlist duration from track count and average length, or get exact song-section duration from bars, BPM, and time signature.
Music Interval Calculator
Find the musical interval between any two notes: get the semitone distance, interval name (Major 3rd, Perfect 5th, etc.), and consonance classification.
Music Scale Calculator
Find all notes in any musical scale: major, minor, pentatonic, modes, and chromatic. Select a root note and scale type to see every note and its position on the chromatic scale.
Music Transposer Calculator
Transpose any note or key up or down by any number of semitones. Shows the resulting note, interval name, and octave shift — essential for arranging and instrument transposition.
NaNoWriMo Word Count Calculator
Track your NaNoWriMo progress: enter your goal, days remaining and words written to get your required daily pace and projected total.
NATO Phonetic Alphabet Calculator
Convert any text into the NATO phonetic alphabet (Alpha, Bravo, Charlie …) — useful for spelling out callsigns, codes and names clearly over radio or phone.
Nautical Mile Calculator
Convert nautical miles to kilometres, statute miles, metres, and feet. Calculate travel time at a given speed in knots.
Nether Portal Calculator
Convert Minecraft Overworld coordinates to Nether coordinates (÷8) so your portals link correctly between dimensions.
New Year's Countdown Calculator
Count down the exact days, hours, and minutes until New Year's Day — pick any target year from 1900 to 3000.
New Year's Resolutions Calculator
Count days until New Year's, track how far through the year a date falls, and monitor progress toward a resolution goal.
Note Frequency Calculator
Find the frequency in Hz of any musical note across all octaves, with wavelength, period and octave neighbours.
Numbers to Letters Calculator
Convert numbers to letters using the A1Z26 code: 1=A, 2=B … 26=Z. Enter a sequence and decode it instantly.
Odd Parity Calculator
Generate the odd parity bit for a binary word, or verify whether a received word with its parity bit satisfies odd parity for error detection.
Oil to Butter Calculator
Convert between oil and butter for baking and cooking substitutions: 1 cup butter = ¾ cup oil, or 1 cup oil = 1⅓ cup butter.
Olga Tokarczuk Books Reading Time Calculator
Estimate how long it takes to read Olga Tokarczuk's novels at your reading speed — from Flights to The Books of Jacob.
Op-Amp Gain Calculator
Calculate op-amp voltage gain, output voltage and gain in dB for inverting and non-inverting amplifier configurations.
Oscar Marathon Calculator
Calculate how many days it takes to watch all Oscar Best Picture nominees (or any film list) at your chosen daily viewing pace.
Oxygen Tank Duration Calculator
Calculate how long an oxygen cylinder lasts given tank pressure, cylinder size, and flow rate.
油漆计算器
根据你的墙面面积、油漆每升的覆盖率和涂刷遍数,算出你需要多少升油漆。
Palindrome Date Calculator
Find palindrome dates for any year — dates whose digit string reads identically forwards and backwards in MM/DD/YYYY, DD/MM/YYYY or YYYY/MM/DD format.
Pallet Calculator
Calculate how many boxes fit on a standard pallet, how many layers stack within a height limit, and the total loaded weight.
Pancake Recipe Calculator
Scale a classic pancake recipe to any number of servings. Get exact ingredient quantities for small, medium or large pancakes.
Paper Thickness Calculator
Calculate how thick a sheet of paper becomes after folding it n times. Each fold doubles the stack — 42 folds theoretically reaches the Moon.
Paper Weight Calculator
Calculate the weight of a stack of paper from its GSM rating and dimensions. Covers A4, A3, US Letter and custom sizes.
Parity Bit Calculator
Calculate the even or odd parity bit for any binary word — shows the complete data word with its parity bit appended.
派对餐饮计算器
根据宾客数量和时长规划派对所需的食物、饮料和冰块采购量。
密码熵与强度计算器
根据密码长度和字符集估算密码强度(熵位数)和近似破解时间。
密码生成器与强度检查器
生成强随机密码,并以熵位数衡量其强度。
铺路石计算器
根据露台面积和铺路石尺寸,计算所需铺路石数量及铺底沙用量。
Paver Sand Calculator
Calculate how much jointing sand you need for a paved area — enter paver size, joint width and depth to get volume and mass.
PCB Impedance Calculator
Calculate PCB trace characteristic impedance for microstrip and stripline geometries using IPC-2141A formulas — FR4 or custom dielectric.
PCB Trace Current Calculator
Calculate the maximum current a PCB copper trace can carry before overheating — IPC-2221 formula for external and internal layers.
PCB Trace Resistance Calculator
Calculate PCB copper trace DC resistance, voltage drop and power loss — enter trace length, width, copper weight and operating temperature.
PCB Trace Width Calculator
Calculate the minimum PCB copper trace width needed to carry a given current without exceeding a temperature rise — IPC-2221 formula.
Pea Gravel Calculator
Calculate how much pea gravel you need by area and depth. Get the volume in m³/yd³, weight in tonnes, and the number of 0.5 ft³ bags to buy.
Perfect Pancake Calculator
Calculate the exact batter ingredients for any number of American-style pancakes at any diameter. Scales flour, milk, eggs and more automatically.
Perfect Pizza Calculator
Calculate the exact dough ingredients (flour, water, salt, yeast, oil) for any number of pizzas at any diameter and crust style.
Period Products Cost Calculator
Calculate the annual and lifetime cost of disposable period products and compare savings with reusable alternatives like menstrual cups.
PERT Calculator
Calculate the PERT expected task duration, standard deviation and confidence intervals from optimistic, most likely and pessimistic time estimates.
Pi Attenuator Calculator
Calculate resistor values for a symmetric Pi (π) attenuator pad — enter attenuation in dB and characteristic impedance.
Picture Frame Calculator
Calculate mat size, glass area, frame outer size and molding length needed to frame any artwork or photo — in inches or centimetres.
Pig Latin Translator
Translate any English text into Pig Latin — consonant clusters move to the end and "ay" is added; vowel-starting words get "way" or "yay".
Pipe Volume Calculator
Calculate the internal volume of a pipe in litres, m³ and US gallons from outer diameter, wall thickness and length.
Pipe Weight Calculator
Calculate the weight of a metal or plastic pipe from outer diameter, wall thickness, length and material density — in kg and lb.
Pitch Diameter Calculator
Calculate gear pitch diameter, outside diameter, root diameter and circular pitch from tooth count and diametral pitch or module.
Pixels Per Inch Calculator
Calculate pixels per inch (PPI) from a pixel count and physical size, or find how many pixels span a given size at a set PPI.
Pixels to Print Size Calculator
Calculate the physical print size of an image in inches and cm from its pixel dimensions and print DPI.
Pizza Calculator
Calculate how many pizzas to order for any group size — choose appetite level, slices per pizza and an optional buffer for seconds.
Pizza Comparison Calculator
Compare two pizzas by price per square inch to find the better deal — because a larger pizza is almost always cheaper per bite.
Pizza Party Calculator
Find out how many pizzas to order for a party based on guest count, appetite and slices per pizza.
Pizza Tip Calculator
Calculate the tip on a pizza order and split the total equally between any number of people.
Plate Weight Calculator
Calculate the total weight on a barbell from the bar weight and number of plates loaded per side, in kg or lb.
Playback Speed Calculator
Calculate how long a video or podcast takes at any playback speed — see time saved vs. normal 1× playback.
Pleated Skirt Calculator
Calculate the fabric length needed to sew a pleated skirt from waist, length, pleat count and depth.
Plywood Calculator
Calculate how many plywood sheets you need to cover a floor, wall or subfloor — with waste allowance and cost estimate.
Podcast Time Calculator
Calculate total weekly, monthly and yearly podcast listening time by episode length, frequency and playback speed.
Pokémon GO Candy Calculator
Calculate how many more Pokémon GO candies you need to evolve, plus catches and buddy walking distance required to collect them.
Poker EV Calculator
Calculate the expected value (EV) of calling a bet in poker. Compare your pot odds to your equity to find whether a call is profitable.
Poker Odds Calculator
Calculate your poker draw probability from the number of outs on the flop or turn, with exact odds and the classic rule-of-2/4 shortcut.
Pomodoro Technique Calculator
Plan your Pomodoro sessions: find how many focused work blocks fit in your available time, with custom break lengths.
Pond Calculator
Calculate pond volume in US gallons and litres for rectangular, oval or circular ponds, plus pump size and fish stocking capacity.
Pool Calculator
Calculate swimming pool volume in US gallons and litres, shock chlorine dose and filter pump size for rectangular, oval or circular pools.
Pool Salt Calculator
Calculate how much pool salt (NaCl) to add to reach the ideal salinity for your salt-chlorine generator.
Pool Shock Calculator
Calculate exactly how much pool shock (chlorine) to add based on pool volume, current chlorine level, and shock product concentration.
Popcorn Calculator
Calculate how many raw kernels (grams, tablespoons, cups) to pop for any number of people, with stovetop, air-popper, and microwave expansion ratios.
Port Length Calculator
Calculate the tube length for a bass-reflex (ported) speaker enclosure using the Helmholtz resonator formula given port diameter, box volume and tuning frequency.
Post Hole Concrete Calculator
Calculate the volume of concrete and number of pre-mix bags needed to fill a post hole, accounting for the post volume displaced inside the hole.
Pounds to Cups Calculator
Convert pounds to US cups for flour, sugar, butter, water, milk, honey and more. Results depend on ingredient density.
PPI / 像素密度计算器
根据分辨率和对角线尺寸,计算显示器的每英寸像素数和点距。
Pregnancy Countdown Calculator
Count down to your due date by days and weeks, see your current trimester, and track how far through pregnancy you are.
Price Per Acre Calculator
Calculate price per acre from a total property price and acreage — with automatic conversions to per hectare, per square foot and per square metre.
Price Per Linear Foot Calculator
Calculate price per linear foot (LF) from a total cost and length — with automatic conversion to price per metre and an optional target-length cost.
Price Per Ounce Calculator
Find the true cost per ounce of any product — compare grocery items, cleaning supplies or cosmetics by their real unit price.
Price Per Pound Calculator
Calculate the price per pound of any product — great for comparing meat, produce, grains or bulk goods sold by weight.
Price Per Round Calculator
Calculate the cost per round of ammunition from a box price and round count. Compare bulk packs to find the cheapest cost per cartridge.
Price Per Square Inch Calculator
Calculate the cost per square inch of any rectangular item — compare pizzas, prints, panels, tiles or any flat surface by true unit area.
Price Per Weight Calculator
Compare food and product prices fairly — convert any price and weight into cost per kg, per lb and per 100 g instantly.
Priming Sugar Calculator
Calculate the exact amount of priming sugar (dextrose, sucrose or DME) needed to carbonate homebrew beer to a target CO₂ volume.
Privacy Fence Calculator
Calculate posts, rails, pickets, and concrete bags needed for a privacy fence, plus a total material cost estimate with editable unit prices.
Projector Calculator
Calculate projector screen size (diagonal, width, height) from throw distance, throw ratio, and aspect ratio. Works for any projector spec.
PTE Score Calculator
Calculate your PTE Academic overall score from Listening, Reading, Speaking and Writing subscores, with CEFR band.
Punch Force Calculator
Calculate the punch (blanking) force and minimum press tonnage needed to punch holes in sheet metal or other materials.
Pyramid Block Calculator
Calculate the total number of blocks or stones needed to build a square stepped pyramid of any base size and step reduction.
Quarantine Books Calculator
Find out how many books you can read during quarantine — enter days, daily reading hours, speed and book length to get a realistic reading total.
Quarantine Food Calculator
Calculate how much food and water to stockpile for a quarantine or emergency, broken down by food group and calorie needs.
Quilt Binding Calculator
Calculate how much binding fabric and how many strips you need to finish a quilt — enter size and binding width.
Quilt Calculator
Calculate how much fabric you need for a quilt: top, backing and binding yardage from quilt size, block size, seam allowance and fabric width.
Quit Smoking Calculator
See how much money you save by quitting smoking — weekly, monthly and yearly — plus your estimated lifetime tobacco spend.
抽奖获奖者选取器
从参赛名单中随机抽取一名或多名获奖者,支持可选的加权票数。
Rafter Length Calculator
Calculate common rafter length from building span and roof pitch using the Pythagorean theorem, with optional eave overhang.
RAID Calculator
Calculate usable capacity, storage efficiency, and fault tolerance for RAID 0, 1, 5, 6, 10, 50 and 60 arrays from disk count and disk size.
Rain to Snow Calculator
Convert a rainfall depth to its snowfall equivalent using the snow-to-liquid ratio (standard 10:1, adjustable for snow density).
Rainfall Volume Calculator
Calculate the total volume of water falling on an area from rainfall depth and catchment dimensions (m² × mm = litres).
RAM Latency Calculator
Convert RAM CAS latency cycles to real nanoseconds using the DDR transfer rate, so you can compare kits on equal footing.
Ramp Slope Calculator
Calculate ramp slope percentage, angle in degrees, ramp surface length, and rise-to-run ratio from vertical rise and horizontal run.
随机颜色生成器
立即生成随机颜色并获取其HEX、RGB和HSL代码。
随机数生成器
在你所选的任意范围内生成一个或多个随机整数——非常适合抽签、挑选、游戏、抽样和快速决策。
随机分队生成器
将名单随机打乱并分成规模均衡的随机队伍。
Reading Speed Calculator
Calculate how long it will take to read a text or book given your reading speed in words per minute (WPM) and the word count.
阅读时间计算器
根据字数和阅读速度估算阅读一段文本所需的时间。
Rebar Calculator
Calculate the weight of steel rebar (reinforcing bar) for construction. Enter the diameter, length and quantity to get weight per bar and total weight in kg.
Recessed Lighting Calculator
Calculate how many recessed (can) lights you need for any room based on size, ceiling height, room type, and fixture lumens.
食谱缩放计算器
通过将每种食材按所需份数缩放,即时将任意食谱翻倍、三倍或减半。
Reorder Point Calculator
Calculate the reorder point (ROP) for inventory management: lead-time demand plus safety stock, so you never run out of stock.
Resolution Scale Calculator
Calculate the scale factor between two display resolutions, check pixel density (PPI), pixel count ratio, and whether aspect ratios match.
Retaining Wall Calculator
Calculate the active lateral earth pressure and total force on a retaining wall using the Rankine method — enter wall height, soil weight, friction angle, and surcharge.
Retirement Countdown Calculator
Count the exact days, months and years remaining until your planned retirement date based on your birth year and target retirement age.
Reverse Text Generator
Instantly reverse any text character-by-character or flip the word order, with character-count and composition stats.
Reverse Time Calculator
Calculate start time from end time and duration, or end time from start and duration — with clock display and 24-hour format.
RF Power Unit Converter
Convert RF power between dBm, milliwatts, dBW, watts, dBμV and microvolts. Instant conversion with 50 Ω load assumption for voltage units.
Rice Water Ratio Calculator
Calculate the exact water-to-rice ratio for white, brown, basmati, jasmine, sushi, wild, and arborio rice — in cups, grams, or mL.
Ring Size Calculator
Convert a finger measurement to ring sizes in EU, US, UK and Japan standards from inner circumference or diameter.
Rip-Rap Calculator
Calculate the volume and weight of rip-rap (angular erosion-control stone) needed for a bank, slope or channel protection project.
River Rock Calculator
Calculate how much river rock (smooth landscaping stone) you need by volume and weight for a garden, path or drainage bed.
Rivet Size Calculator
Find the correct rivet diameter, body length and drill hole size for blind (pop) or solid rivets based on total material thickness.
Road Base Calculator
Calculate the cubic metres and tonnes of road base (crushed aggregate) needed for a driveway, path or sub-base, with a compaction factor.
Roll Length Calculator
Calculate the total length of material wound on a roll from outer diameter, core diameter and material thickness.
Rolling Offset Calculator
Calculate the true (rolling) offset, travel and run for a pipe or conduit that must change both height and direction simultaneously.
Roof Pitch Calculator
Calculate roof pitch angle, slope factor and rafter length from rise and run; enter building span for the actual rafter cut length.
Roof Shingle Calculator
Calculate the exact number of individual shingles and bundles needed from roof area, shingle size, exposure, and waste.
Roof Truss Calculator
Calculate rafter length, peak rise, pitch angle and pitch factor from building span and roof pitch for truss design.
Roofing Calculator
Estimate all roofing materials: squares of shingles, underlayment rolls, ridge cap bundles, starter strip and drip edge from building dimensions and pitch.
屋顶瓦片与平方数计算器
根据屋顶占地面积和坡度,估算屋顶覆盖平方数和瓦片捆数,包含屋脊和切割损耗。
房间空调与取暖器BTU计算器
根据房间面积、日照、层高和人数,计算空调或取暖器所需BTU容量。
Round Pen Calculator
Calculate how many panels you need to build a round horse pen, the total fencing length, enclosed area and optional material cost.
Rounds Per Minute Calculator
Calculate rounds per minute (RPM) from a count and time, or convert RPM to time between rounds, rounds per second, and rounds per hour.
RPM Calculator
Convert RPM to angular velocity (rad/s), frequency (Hz), period, and peripheral speed — for motors, engines, wheels, and fans.
Rug Size Calculator
Find the recommended rug size for a living room, dining room, or bedroom from room and furniture dimensions, with the nearest standard rug size.
Rust Decay Calculator
Estimate how much steel or iron has corroded over time and when it will rust through, based on ISO 9224 environment corrosion rates.
Sag Calculator
Calculate the sag (mid-span deflection) and cable length of a wire or cable between two supports using the parabolic and catenary formulas.
Salad Calories Calculator
Count the calories in your salad ingredient by ingredient — greens, protein, cheese, dressing and more — using standard USDA calorie densities.
Salt Dough Calculator
Scale the classic 2:1:1 salt dough recipe by batch count — get exact flour, salt and water amounts in cups or grams.
Sand Calculator
Calculate how much sand you need by volume (m³, yd³) and weight (tonnes, kg) from area length, width and depth. Supports metric and imperial.
Sandbox Calculator
Calculate how many litres of play sand you need for a sandbox, plus total weight and the number of standard bags to buy.
SAT Score Calculator
Add your SAT Math and EBRW section scores to get your composite score (400–1600) and an approximate national percentile.
Screen Ratio Calculator
Calculate the aspect ratio, pixel diagonal, megapixels, PPI and pixel pitch of any screen from its resolution and optional physical size.
屏幕尺寸计算器
将屏幕的对角线尺寸和宽高比转换为实际宽度、高度和面积。
Sealant Calculator
Calculate how many tubes of sealant or caulk you need to fill a gap or joint — by length, width, depth and tube size.
Self-Rising Flour Calculator
Convert all-purpose flour to self-rising flour: find the exact baking powder and salt to add per cup.
Semester Grade Calculator
Calculate your weighted semester grade average across up to 5 courses weighted by credit hours.
Semitone Calculator
Calculate semitones between two frequencies, or find the target frequency a given number of semitones away.
Sentence Case Converter
Convert any text to sentence case: first letter of each sentence capitalised, everything else lowercase. Handles "I" and multi-sentence paragraphs.
Sex Calculator
Estimate calories burned during sexual activity by body weight, duration and intensity, using MET values from Ainsworth's Compendium (2011).
Shiplap Calculator
Calculate how many shiplap boards you need for a wall. Enter wall size, board length and exposure width to get board count, rows and linear footage with waste.
Shoe Size Conversion Calculator
Convert shoe sizes between US Men's, US Women's, UK, EU (European), Japan and foot length in cm.
Shoelace Length Calculator
Calculate the correct shoelace length for criss-cross, straight or display lacing from eyelet count, shoe width and row spacing.
Shower Cost Calculator
Calculate the water and energy cost of a shower from duration, flow rate, and your local utility prices.
Shutter Speed Calculator
Calculate the correct shutter speed from aperture, ISO and scene brightness (EV). Covers sunny through candlelight conditions.
Siding Calculator
Calculate how many squares of exterior siding you need from house dimensions, gables, openings and waste allowance. Supports metric and imperial.
Signal Propagation Delay Calculator
Calculate one-way and round-trip signal propagation delay for fiber, coaxial cable, twisted pair and vacuum. Results in ns, µs or ms.
Silver Lining Calculator
Quantify the benefits hidden in a setback. Enter the loss and up to 3 silver lining benefits to find how much of the negative is offset.
Size to Weight Calculator
Calculate the weight of any rectangular box or block from its length, width and height, using standard material densities or a custom value.
Slack Time Calculator
Calculate total slack (float) for a project activity from Early Start, Early Finish and Late Finish — identifies critical-path activities.
Small Caps Text Generator
Convert any text to Unicode small capital letters instantly. Paste into social media, documents or websites — no font needed.
Small Text Generator
Convert normal text to Unicode small caps, superscript, or subscript characters — copy the tiny text instantly.
Snow Load Calculator
Calculate the snow load on a roof in pounds and psf using the ASCE 7 simplified method — enter snow depth, type, roof area, and slope.
Snowman Calculator
Calculate how much snow you need to build a snowman: total volume in litres and weight in kg for three stacked spheres.
Social Media Ban Impact Calculator
Estimate the hours, financial value, books, workouts and kilometres you gain from a social media ban or digital detox.
Social Media Time Alternatives Calculator
See what you could achieve with the time you spend on social media: books read, workouts completed, languages learned, and films watched.
Sock Size Calculator
Find your sock size in EU, UK and US systems from foot length in cm — with size-range indicator and instant cross-system conversion.
Socks Loss Index Calculator
Estimate how many socks disappear in the laundry each year, your annual replacement cost, and your personal Socks Loss Index score (0–10).
草皮计算器
计算覆盖草坪所需的草皮卷或托盘数量,包含修剪损耗量。
Sofa Size Calculator
Find the ideal sofa length and depth for your room: enter dimensions and seats needed to get recommendations that keep traffic clearance.
Sonotube Calculator
Calculate the concrete volume and bags needed to fill a sonotube (cylindrical cardboard form) for footings, fence posts and columns.
Sourdough Calculator
Calculate flour, water, starter and salt weights for any sourdough loaf using baker's percentages.
Speaker Box Calculator
Design a sealed speaker enclosure: compute optimal box volume, system resonance and −3 dB cutoff from Thiele-Small parameters.
Speedometer Gear Calculator
Find your true speed after changing tyre sizes — the speedometer error and correction factor from old to new tyre dimensions.
Spindle Spacing Calculator
Calculate the equal gap between deck or stair balusters and check it against the US IRC 4-inch building code limit.
Spindle Speed Calculator
Calculate the correct CNC or lathe spindle speed (RPM) from cutting speed and tool/workpiece diameter in metric or imperial.
Spiral Staircase Calculator
Calculate rise, going at the walking line, rotation per step, and stringer length for a spiral staircase.
Square Feet to Cubic Yards Calculator
Convert square feet and a depth in inches to cubic yards of material. Ideal for concrete, gravel, mulch, topsoil and landscaping projects.
平方英尺计算器
根据长度和宽度,以平方英尺和平方米计算矩形房间或空间的面积,并可选地估算材料总成本。
Square Meter Calculator
Calculate the area of a rectangular space in square metres from its length and width. Supports metres, cm, mm, feet, inches and yards as input.
Square Yard Calculator
Convert square yards to square feet, square metres, acres, hectares, and more — or convert any area unit to square yards.
Square Yards Calculator
Calculate area in square yards from length and width in feet, meters, inches or yards — plus instant conversion to other area units.
Stair Carpet Calculator
Calculate the carpet area needed for stairs from number of steps, tread depth, riser height and stair width, with waste and cost.
楼梯斜梁计算器
根据总高差计算楼梯踢板、踏板和斜梁长度,并检查2R+T舒适性规则。
Stairs Calculator
Calculate stair riser height, tread going, stringer length and pitch angle from total rise and number of risers.
Standing Desk Height Calculator
Find the ideal standing desk height for your body — plus monitor height and eye level — based on ergonomic elbow-height rules.
Star Wars Marathon Calculator
Calculate total watch time for any Star Wars marathon — original trilogy, all 9 episodes, or all 11 films — with custom breaks and daily pacing.
Steak Cook Time Calculator
Calculate steak cooking time by thickness, doneness, and method (cast iron, grill, or reverse sear) — with rest time and internal temperature target.
Steel Plate Weight Calculator
Calculate the weight of a steel or metal plate from its length, width and thickness in millimetres.
Steel Weight Calculator
Calculate the weight of steel round bar, square bar, flat bar, hollow tube or hex bar in kg from dimensions.
Stone Calculator
Calculate how many tonnes of decorative stone, pebbles or chippings you need by area and depth, with bag count and cost estimate.
Streaming Bitrate Calculator
Calculate video file size or data usage from video bitrate, audio bitrate and duration. Covers SD, HD and 4K streams.
Streaming Royalties Calculator
Estimate music streaming earnings by platform. Enter stream count, choose Spotify, Apple Music or Tidal, and set your artist royalty split.
Strikethrough Text Generator
Convert text to copy-pasteable Unicode strikethrough that works in WhatsApp, Telegram, Discord, Instagram and most messaging apps without rich-text formatting.
子网 / CIDR 计算器
输入IPv4地址和前缀(CIDR),获取网络地址、广播地址、可用主机范围、主机数量和子网掩码。
Subscript Generator
Convert digits, math operators, and common letters to unicode subscript characters — copy-paste ready for H₂O, CO₂, x₁ and other formulas.
订阅费用计算器
将所有流媒体和应用订阅费用汇总为每月和每年的总额。
Sulfur Calculator
Calculate sulfur (SO₂) emissions from burning coal, oil or diesel by entering the fuel mass and its sulfur content by weight.
Sunglasses Lens Category Calculator
Find the right EU lens category (Cat 0–4) for your sunglasses based on UV index, activity type and eye sensitivity.
Sunscreen Amount Calculator
Calculate exactly how much sunscreen you need per application and per day based on your body surface area and coverage area.
Sunscreen Calculator
Estimate how long your sunscreen protects you based on SPF, skin type and UV index — with UVB-blocking percentage.
Superscript Generator
Convert text to Unicode superscript characters instantly — digits, letters and common symbols, ready to copy and paste anywhere.
T9 to Text Converter
Convert a T9 digit sequence to possible letter combinations. Shows the primary mapping, all combos for short sequences, and letters per key.
Tablecloth Size Calculator
Find the right tablecloth size for rectangular or round tables. Enter table dimensions and desired drop length to get cloth length, width, and area.
Taco Bar Calculator
Plan a taco bar for any crowd: get tortilla count, protein, cheese, salsa, guacamole, sour cream and beans in shopping-ready quantities.
Takt Time Calculator
Calculate takt time — the maximum cycle time allowed per unit to meet customer demand — from available production time and daily demand.
Tank Volume Calculator
Calculate the volume of a cylindrical, rectangular, or spherical tank in litres, US gallons, UK gallons and cubic metres.
Taper Calculator
Calculate the included taper angle, half-angle, taper per foot (or per 300 mm) and taper ratio from two diameters and a length.
Tea Brewing Calculator
Get the recommended water temperature, steep time and leaf quantity for black, green, white, oolong, herbal, pu-erh and other teas.
Tent Size Calculator
Calculate the minimum tent floor area for your group — choose comfort level and whether to include gear storage inside.
Tesla Charging Cost Calculator
Calculate the electricity cost and time to charge a Tesla from any charge level to a target, given your kWh rate and charger output.
Test Grade Calculator
Calculate your test score as a percentage, get your letter grade (A–F), and see pass/fail against a custom threshold.
Text to Binary Converter
Convert any text to its 8-bit binary representation — each character becomes its ASCII code in binary, with character counts and a type breakdown.
Text to Hex Converter
Convert any text string to hexadecimal — see each character's Unicode code point as an upper-case hex pair.
Thanksgiving Calculator
Find the exact date of US Thanksgiving (4th Thursday of November) for any year from 1863 onward.
Thanksgiving Calories Calculator
Estimate the calories in your Thanksgiving meal — enter servings of turkey, stuffing, sides, and pie to see the total.
Thinset Calculator
Estimate how many 50 lb bags of thinset mortar you need for any tiling job based on area, trowel notch size and a waste allowance.
Thread Calculator
Calculate pitch diameter, minor diameter, thread depth and lead angle for metric ISO and unified (UNC/UNF) screw threads.
Thread Pitch Calculator
Calculate thread pitch, TPI, lead, pitch diameter and minor diameter for metric ISO and unified inch (UNC/UNF) screw threads.
Tickets Calculator
Calculate the total cost for event tickets including service fees and group or promo discounts.
Tie Length Calculator
Find the right necktie length for your height and knot style — regular, long or extra-long.
TikTok Time Alternatives Calculator
See how many books, movies, courses or 5K runs you could fit into the time you spend on TikTok each year.
瓷砖计算器
根据房间面积和瓷砖尺寸算出地面需要多少块瓷砖,并为切割和破损预留损耗量。
Time Adder Calculator
Add up to four time durations (hours, minutes, seconds) and get the total in H:MM:SS, total minutes and total seconds.
Time Difference Calculator
Find the exact time difference between two clock times in hours, minutes and seconds — including overnight spans.
Time to Decimal Calculator
Convert hours, minutes and seconds to decimal hours instantly. Perfect for payroll, billing and spreadsheet time entries.
Time to Hours Conversion Calculator
Convert any combination of days, hours, minutes and seconds into total hours, minutes, seconds and weeks.
Time Until Calculator
Calculate exactly how many days, hours and minutes remain until any future date — or how long since a past date.
Time-Lapse Calculator
Calculate how many frames you need, how long your time-lapse video will be, and how fast the world appears to move.
Timecode to Frame Number Calculator
Convert SMPTE timecode (HH:MM:SS:FF) to an absolute frame number for any frame rate, with drop-frame support for 29.97 and 59.94 fps.
小费计算器
算出小费、账单总额和每人金额——非常适合分摊餐厅账单。
Tip from Net Price Calculator
Calculate the tip on the pre-tax (net) price, add sales tax, and split the total among any number of people.
Tire Size Calculator
Calculate tire outer diameter, sidewall height, circumference, and revolutions per mile from the P-metric tire code.
Title Case Converter
Convert text to title case, sentence case, UPPER CASE, lower case, camelCase, or PascalCase instantly.
Toilet Paper Calculator
Find out how long a toilet paper roll or pack lasts for your household based on sheets per roll, usage per visit, and number of people.
Tonnage Calculator
Estimate how many tons of air conditioning (HVAC tonnage) you need for a room or building using floor area, climate, insulation and occupancy.
Toothpaste Calculator
Calculate how long a tube of toothpaste lasts based on tube size, amount per brushing, frequency and number of people sharing it.
表层土计算器
根据面积和填充深度,估算花圃或草坪所需的表层土体积、重量和袋数。
总拥有成本计算器
估算含运营成本和残值的汽车或家电的完整拥有成本。
Total Harmonic Distortion (THD) Calculator
Calculate THD % from the fundamental and harmonic amplitudes (up to 5th). Formula: √(V₂²+V₃²+…) / V₁ × 100.
Traffic Density Calculator
Calculate traffic density (vehicles/km or mile) from flow and speed using the fundamental equation k = q ÷ v, with Level of Service bands.
Travel Job Application Calculator
Compare a job offer in another city by adjusting the salary for cost-of-living, relocation costs, and signing bonus to find your real annual gain.
Trick-or-Treat Calculator
Estimate your Halloween candy haul: pieces, weight and calories based on neighborhood type, hours out, candy per house and age.
True Position Calculator
Calculate GD&T true position deviation for a feature, check pass/fail against the tolerance zone, and add bonus tolerance from MMC.
Calculate how US import tariffs raise the landed cost of goods — enter unit price, the applicable tariff rate, and quantity to get the total after-tariff price.
Turbo Size Calculator
Estimate the required turbocharger compressor airflow, pressure ratio and outlet temperature for a target horsepower goal on a gasoline engine.
Turkey Cooking Time Calculator
Calculate how long to cook a turkey by weight at 325°F or 350°F for stuffed or unstuffed birds, based on USDA guidelines, with an estimated done time.
Turkey Defrost Calculator
Calculate how long to defrost a frozen turkey using the refrigerator, cold water or microwave method, based on USDA food safety guidelines.
Turkey Size Calculator
Find out how many pounds of turkey to buy for any number of guests — whole bird, bone-in breast or boneless roast, with or without leftovers.
Turkey Thawing Calculator
Calculate how long to thaw a frozen turkey using three USDA-approved methods: refrigerator, cold water and microwave.
TV Alternatives Calculator
Calculate the annual time and money cost of your TV habit and see what you could accomplish with the same hours and dollars.
TV Mounting Height Calculator
Calculate the ideal height to mount a TV on the wall so the screen centre aligns with your seated eye level for comfortable viewing.
TV Series Duration Calculator
Calculate total watch time for any TV series by entering seasons, episodes per season and episode length, then see how many days it will take.
TV Size & Viewing Distance Calculator
Find the ideal viewing distance for your TV size and resolution, or the best TV size for your room distance, using SMPTE viewing-angle standards.
打字速度计算器(WPM)
通过计时测试计算每分钟打字字数、净WPM和准确率。
UK to US Shoe Size Converter
Convert UK shoe sizes to US, EU, AU and Japanese sizes for men's and women's footwear, with estimated foot length.
Uncooked to Cooked Rice Calculator
Convert any amount of dry uncooked rice to its cooked weight, volume, servings and water needed — by variety.
Underline Text Generator
Generate underlined text using Unicode combining characters or HTML tags — copy-paste into social media, chats or web pages.
单价计算器
通过每单位价格比较两款产品,找出更便宜的选择——破解误导性的包装规格,每次都挑出最超值的。
Upload Time Calculator
Calculate how long a file upload will take given its size (MB, GB, TB) and your upload speed in Mbps.
Upside Down Text Generator
Flip any text upside down using Unicode look-alike characters — great for social media bios, captions, and fun messages.
正常运行时间 / SLA 停机时间计算器
将可用性 SLA 百分比(如 99.9%)转换为每天、每周、每月和每年允许的停机时间。
Uptime Calculator
Calculate the allowed downtime per year, month, week, and day for any uptime SLA percentage — from 90 % (one nine) to 99.9999 % (six nines).
US Pay Gap Calculator
Calculate the pay gap between any two salary figures. Defaults to U.S. median earnings by gender (BLS 2023). Shows gap %, cents-per-dollar and lifetime difference.
US to EU Shoe Size Calculator
Convert US shoe sizes to EU (European) sizes and back for men and women — with UK size and approximate foot length in cm and inches.
US to UK Shoe Size Calculator
Convert US shoe sizes to UK (British) sizes for men and women — with EU equivalent and approximate foot length in cm and inches.
Vacation Countdown Calculator
Count the exact days, weeks, and hours until your next vacation. Enter the departure date to see a live countdown and progress bar.
Vertical Curve Calculator
Calculate the K-value, high/low point and elevation profile of a parabolic vertical curve for highway and road design.
Vertical Exaggeration Calculator
Calculate the vertical exaggeration (VE) of a topographic cross-section or map profile from the horizontal and vertical scale denominators.
Video File Size Calculator
Estimate the file size of a video from its duration, video bitrate and audio bitrate. Shows MB, GB, video/audio split and clips per storage card.
Video Frame Size Calculator
Calculate the uncompressed size of a single video frame in bytes, the megapixel count, aspect ratio and uncompressed data rate.
Vigenère Cipher Calculator
Encrypt or decrypt text using the Vigenère polyalphabetic substitution cipher with any keyword.
Vinyl Fence Calculator
Calculate posts, panels, rails, caps and pickets for a vinyl (PVC) fence from total length and height.
Vinyl Fence Cost Calculator
Estimate the total cost of a vinyl fence project including panel materials, labor and post costs.
Vinyl Siding Calculator
Calculate squares and linear feet of vinyl siding needed from wall area, window/door deductions and waste.
Vocal Range Calculator
Enter your lowest and highest MIDI note numbers to find your vocal range in semitones and octaves, frequency span, and approximate voice type.
Wage Gap Calculator
Compare two salaries to calculate the wage gap percentage, pay ratio, hourly earnings gap and 40-year career difference.
Wainscoting Calculator
Calculate wainscoting panel area, chair rail, base moulding and stile quantities from room length, width and panel height.
Wallpaper Calculator
Calculate how many wallpaper rolls you need from total wall area, roll dimensions and pattern repeat — with a customisable waste allowance.
墙纸卷数计算器
根据房间尺寸、卷材规格和图案循环,计算所需墙纸卷数,并已考虑裁切和损耗。
Water Cooling Calculator
Calculate the coolant temperature rise ΔT for a PC water-cooling loop: enter the heat load (TDP), flow rate, and coolant type to find outlet temperature and optimal pump speed.
Wedding Alcohol Calculator
Calculate how many bottles of wine, cases of beer, and spirit bottles to buy for a wedding reception based on guests, hours, and drinking style.
Wedding Countdown Calculator
Count the exact days, weeks and months until (or since) your wedding — enter year, month and day for an instant countdown.
Week Calculator
Convert any number of weeks to days, hours, minutes, seconds, months and years instantly. Fractional weeks are supported.
Weekday Calculator
Find the day of the week for any date — enter a year, month and day to instantly see Monday, Tuesday … and whether it is a weekday or weekend.
Weighted Blanket Calculator
Find the ideal weighted blanket weight for adults, children, or seniors — based on the standard 7–12% of body weight occupational therapy guideline.
Welding Calculator
Calculate welding heat input (kJ/mm), arc energy, arc power, and total weld time from voltage, current, and travel speed.
Well Volume Calculator
Calculate the volume of water stored in a cylindrical well casing from its inside diameter and water column depth, in gallons, litres, and cubic feet.
What Grade Was I In Calculator
Enter your birth year and a school year to instantly find what grade you were in — from Kindergarten to 12th grade.
Wheel Horsepower Calculator
Convert between engine (flywheel) horsepower and wheel (dyno) horsepower by accounting for drivetrain losses in FWD, RWD, and AWD vehicles.
Wheel Offset Calculator
Calculate wheel backspacing and how changing the ET offset moves your wheels inward or outward — enter rim width, current offset, and target offset.
轮椅坡道坡度计算器
根据给定高差计算坡道长度和坡度,并与 ADA 1:12 最大值进行比较。
White Christmas Calculator
Find the probability of a White Christmas and project how many snowy holidays to expect over any number of future years.
Winch Size Calculator
Calculate the minimum rated winch capacity needed to recover a vehicle on a slope, accounting for terrain friction and a safety factor.
Wind Chill Calculator
Calculate the wind-chill temperature using the official NWS/Environment Canada 2001 formula for air temperature and wind speed in metric or imperial units.
Windsock Calculator
Convert wind speed to the windsock angle and Beaufort number. Enter speed in km/h, knots, m/s or mph.
Witcher Calculator
Calculate how much XP you need and how long it will take to reach a target level in The Witcher 3: Wild Hunt.
Witcher Monster Slayer Calculator
Estimate average damage per round and rounds to defeat a monster in The Witcher: Monster Slayer AR mobile game.
Wizarding Currency Calculator
Convert between Galleons, Sickles and Knuts from the Harry Potter universe using the canon exchange rates from the books.
Wood Beam Span Calculator
Calculate the maximum safe span for a wood joist or beam given lumber size, species, load and deflection limit per NDS 2018 design values.
Wood Fence Calculator
Estimate the number of fence posts, boards, rails and concrete bags needed to build a wood fence — with a waste allowance and gate opening deduction.
Words Per Minute Calculator
Calculate your typing, reading, or speaking speed in words per minute from a word count and elapsed time.
Working Days Calculator
Count the number of working days (Monday to Friday) between two dates, with optional deduction for public holidays.
Years Between Dates Calculator
Calculate the exact number of years, months, weeks and days between any two calendar dates — works as an age calculator too.
Yeast Converter
Convert between active dry yeast, instant/rapid-rise yeast and fresh compressed yeast using standard baking ratios.
Yes or No Calculator
Get a random Yes or No answer in a fair 50/50 coin flip. Tracks your session results so you can see the running yes/no split.
是或否决策器
让随机性来决定:以可调概率获得随机的「是」或「否」答案,并查看概率分布。
Zombie Invasion Calculator
Simulate a zombie outbreak using an SI epidemic model — enter population, bite rate and defence to see how fast the horde grows.
5-Number Summary Calculator
Calculate the 5-number summary (min, Q1, median, Q3, max), IQR, range, and Tukey outlier fences from any data set.
A/B Test Calculator
Calculate A/B test statistical significance: enter visitor and conversion counts for control and variant to get the p-value, z-statistic, and relative lift.
Absolute Uncertainty Calculator
Propagate absolute uncertainties through addition, subtraction, multiplication, and division using in-quadrature rules.
Accuracy Calculator
Calculate classification accuracy, precision, recall, F1 score, specificity and NPV from a confusion matrix (TP, TN, FP, FN).
ANOVA Calculator
Run a one-way ANOVA F-test from group summary statistics (n, mean, SD) and get the F statistic, p-value, and effect size.
Ascending Order Calculator
Sort any list of numbers in ascending or descending order instantly — also shows min, max, range and median.
贝叶斯定理计算器
利用灵敏度和假阳性率,通过贝叶斯法则将先验概率更新为后验概率。
Benford's Law Calculator
Check whether a dataset conforms to Benford's Law using a chi-square test and MAD — useful for fraud detection and data validation.
Bertrand Box Paradox Calculator
Explore the Bertrand box paradox: set box counts (GG, GS, SS) and calculate the conditional probability that the second coin is gold given the first was gold.
Bertrand Paradox Calculator
Explore the Bertrand paradox: three valid definitions of a random chord in a circle yield three different probabilities.
Beta Distribution Calculator
Compute the PDF, CDF, mean, variance and mode of the Beta distribution for any shape parameters α and β.
二项分布概率计算器
计算 n 次试验中恰好 k 次、至多或至少 k 次成功的二项概率,以及均值和方差。
Birthday Paradox Calculator
Find the minimum group size for a target probability of two people sharing a birthday — the counterintuitive birthday paradox solved with interactive math.
生日悖论计算器
任意群体规模和天数下,至少两人同天生日的概率。
Bonferroni Correction Calculator
Calculate the Bonferroni-corrected p-value threshold for multiple hypothesis tests to control the family-wise error rate (FWER).
Box Plot Calculator
Calculate min, Q1, median, Q3, max, IQR and outlier fences from a dataset, with a box-plot number line.
Boy or Girl Paradox Calculator
Explore the boy-or-girl probability paradox: how knowing a child is a boy changes the probability that both children are boys.
纸牌概率计算器
不放回从牌堆中抽取 n 张时,恰好 k 张或至少一张有利牌的概率。
Central Limit Theorem Calculator
Calculate the standard error of the mean and sampling distribution using the Central Limit Theorem. Shows 68%, 95%, and 99.7% intervals.
Chebyshev's Theorem Calculator
Apply Chebyshev's inequality to find the minimum proportion of data within k standard deviations of the mean — valid for any probability distribution.
卡方拟合优度检验计算器
使用卡方检验测试观测计数是否与期望计数或比例匹配。
卡方独立性检验计算器
从列联表检验两个分类变量之间的关联性。
Class Width Calculator
Calculate the class width for a grouped frequency distribution: (maximum − minimum) ÷ number of classes, with rounding guidance.
Coefficient of Determination Calculator (R²)
Calculate R² from actual and predicted values. Shows SS_res, SS_tot, residual stats and an actual-vs-predicted plot.
变异系数计算器
从数据或汇总统计量计算变异系数(CV = SD/mean),以百分比表示。
Cohen's d Calculator
Calculate Cohen's d, Hedges' g and Glass's Δ from two group means, SDs and sample sizes.
n 次抛硬币中(公平或有偏)恰好、至少或至多 k 次正面朝上的概率。
Coin Flip Streak Calculator
Find the probability of getting at least one streak of k consecutive heads in n coin flips (fair or biased).
Coin Flipper Calculator
Simulate flipping a fair or biased coin up to 200 times and see the heads/tails breakdown, longest streaks and distribution.
条件概率计算器
从联合概率和 P(B) 求 P(A 在 B 条件下),并检验两事件是否独立。
置信区间计算器
使用 z 分布计算均值的置信区间。免费的在线置信区间计算器,适用于 90%、95% 和 99% 水平,显示误差幅度、下界和上界。
Confusion Matrix Calculator
Calculate Matthews Correlation Coefficient (MCC), Cohen's Kappa and a full confusion matrix from TP, TN, FP and FN counts.
Constant of Proportionality Calculator
Find k in the direct proportion y = kx from any (x, y) pair and predict y for any new x value.
Continuity Correction Calculator
Apply continuity correction to approximate a binomial probability using the normal distribution. Enter n, p and k to get the corrected z-scores and probability.
Correlation Calculator
Compute Pearson r, r², regression slope, and t-statistic between two data sets with a live scatter plot and regression line.
相关系数计算器
计算两个数据集之间的皮尔逊相关系数 (r),以衡量它们线性关系的强度和方向。免费的在线相关性计算器,带有 r² 和斜率。
协方差计算器
计算两个等长变量 x 和 y 的样本或总体协方差。
Critical Value Calculator
Find the critical value for z, t, chi-square, or F distributions given a significance level and tail type.
Cubic Regression Calculator
Fit a cubic polynomial y = dx³ + cx² + bx + a to your data using least-squares regression. Shows R², all 4 coefficients and a prediction.
Decile Calculator
Calculate all nine deciles (D1–D9) for any data set. Deciles divide data into ten equal parts at the 10th, 20th, … 90th percentiles.
Decimal Odds Calculator
Convert decimal (European) odds to payout, profit and implied win probability for any stake.
Degrees of Freedom Calculator
Calculate degrees of freedom for one-sample t-test, two-sample t-test, Welch's t-test, one-way ANOVA and chi-square tests.
描述性统计计算器
为任意数据集计算均值、中位数、众数、极差、方差和标准差。
Dice Average Calculator
Find the expected average, standard deviation, min and max for rolling any number of dice — d4 through d100 or custom sides.
Dice Calculator
Calculate the expected value, min, max, variance, and standard deviation for any dice expression (NdS + modifier).
骰子概率计算器
掷任意数量和类型骰子得到目标总点数(恰好、至少或至多)的概率。
Dispersion Calculator
Calculate all key measures of statistical dispersion — range, variance, standard deviation, IQR and MAD — from a list of numbers.
Dot Plot Calculator
Enter a data set to compute mean, median, mode, range and standard deviation, with a distribution curve showing data spread and key markers.
Effect Size Calculator
Convert between effect size measures: Cohen's d, Pearson r, eta-squared, Cohen's f, odds ratio and probability of superiority.
经验法则(68-95-99.7)计算器
将 68-95-99.7 规则应用于正态数据集:获得一、二、三个标准差区间和百分比。
Error Propagation Calculator
Propagate measurement uncertainties through addition, subtraction, multiplication, division, and power operations using standard error-propagation formulas.
期望值与方差计算器
从离散概率分布表计算期望值、方差和标准差。
指数分布计算器
对给定速率求指数概率 P(X<x) 和 P(X>x),以及均值和方差。
Exponential Growth Prediction Calculator
Predict a future value using two known data points by fitting a continuous exponential growth model P(t) = P₀·e^(rt).
Exponential Regression Calculator
Fit an exponential curve y = a·e^(bx) to data points using least-squares linearisation and compute R² goodness-of-fit.
F-Statistic Calculator
Calculate the F-statistic and two-tailed p-value to test whether two sample variances are significantly different.
False Positive Calculator
Calculate false positive rate, false discovery rate, PPV and NPV for any diagnostic test given prevalence, sensitivity and specificity.
False Positive Paradox Calculator
See how a rare condition causes most positive test results to be false positives, even with a highly accurate test.
First Quartile Calculator
Calculate Q1 (the first quartile / 25th percentile) for any data set using the Tukey hinges method, with the five-number summary and IQR.
Fisher's Exact Test Calculator
Compute the exact p-value for a 2×2 contingency table using Fisher's exact test, plus odds ratio and 95% CI.
五数概括计算器
从数据集获取最小值、Q1、中位数、Q3、最大值和四分位距,用于箱形图摘要。
Five Star Rating Calculator
Calculate the weighted average star rating, Bayesian average and positive review percentage from a 5-star distribution.
Fractional Odds Calculator
Convert fractional betting odds (e.g. 5/2) to decimal odds, implied probability, and potential payout.
Frequency Distribution Calculator
Build a grouped frequency distribution from any data set: class boundaries, frequencies, relative frequencies and cumulative counts.
Frequency Polygon Calculator
Plot a frequency polygon and compute the weighted mean and standard deviation from grouped data class midpoints and frequencies.
几何分布计算器
计算首次成功发生在第 k 次试验的概率,以及累积概率、均值和方差。
Greatest to Least Calculator
Arrange any list of numbers from greatest to least (descending order) instantly, with min, max, range, mean and median.
Histogram Calculator
Build a frequency histogram from any dataset: enter comma-separated values, choose the number of bins, and see counts, relative frequencies, mean and standard deviation.
超几何分布计算器
从规模为 N 的有限总体中不放回地抽取 n 个,恰好抽到 k 个成功的概率。
Hypothesis Testing Calculator
Perform a one-sample z-test: enter sample mean, population mean, std dev and n to get z-statistic, p-value and a reject/fail-to-reject decision.
Implied Probability Calculator
Convert American, decimal or fractional betting odds to implied probability and strip out the bookmaker vig.
Index of Qualitative Variation (IQV) Calculator
Calculate the Index of Qualitative Variation (IQV) to measure diversity or dispersion across nominal categories — from 0 (no variation) to 1 (maximum variation).
Inverse Normal Distribution Calculator
Find the z-score or x value for a given cumulative probability under a normal distribution. Enter p, mean and standard deviation.
IQR 与异常值计算器
计算数据集的四分位距、Tukey 围栏,并标记异常值。
IQR Calculator
Find the interquartile range, quartiles, and five-number summary for any data set — with a normal-distribution visualization of the IQR.
Joint Probability Calculator
Calculate the joint probability P(A∩B), the union P(A∪B), and conditional probabilities P(A|B) and P(B|A) for two events.
Least to Greatest Calculator
Sort a list of numbers from least to greatest (ascending order) and see the min, max, range, median, and mean.
Least to Greatest Decimals Calculator
Sort a list of decimal numbers from least to greatest with preserved precision. Also shows min, max, range, median, and mean.
线性回归计算器
拟合最小二乘直线:斜率、截距、R²、方程及指定值处的预测。
Lognormal Distribution Calculator
Calculate the mean, median, mode, variance, PDF and CDF of a lognormal distribution from its log-mean μ and log-standard deviation σ.
Lottery Odds Calculator
Calculate lottery jackpot odds and prize-tier probabilities for any pool size and draw count using combinations.
Lower Fence Calculator
Calculate the lower fence (Q1 − 1.5 × IQR) and upper fence to identify statistical outliers in a dataset using Tukey's box-plot method.
Mann-Whitney U Test Calculator
Compute the Mann-Whitney U statistic, z-score and two-tailed p-value for two independent groups using the normal approximation.
误差幅度计算器
在选定置信水平下计算均值或比例的误差幅度。
McNemar's Test Calculator
Run McNemar's chi-square test on a paired 2×2 table to compare two proportions from the same subjects.
Mean Absolute Deviation (MAD) Calculator
Calculate the mean absolute deviation, mean, median, range, and standard deviation of any data set.
Mean, Median & Mode Calculator
Calculate mean, median, mode, range and standard deviation for any list of numbers. Paste or type your data set.
Median Absolute Deviation Calculator
Calculate the median absolute deviation (MAD) of a dataset — a robust alternative to standard deviation that resists outliers.
Median Calculator
Find the median, Q1, Q3, interquartile range, mode and range of any dataset — enter numbers separated by commas.
Midrange Calculator
Calculate the midrange of a data set — the average of the minimum and maximum values — instantly from any list of numbers.
Min Max Calculator
Find the minimum and maximum values in any data set, plus range, mean, and median — with a number line visualization.
Mode Calculator
Find the mode (most frequently occurring value) of any dataset, with frequency breakdown and support for bimodal and multimodal data.
Moneyline Odds Calculator
Convert moneyline odds to implied probability, decimal odds, fractional odds, and calculate your potential payout on any wager.
Monty Hall Problem Calculator
Calculate the exact win probability for staying or switching in the Monty Hall problem — generalised to any number of doors and host reveals.
MSE Calculator
Calculate Mean Squared Error (MSE), Root MSE (RMSE), Mean Absolute Error (MAE), and R² from actual and predicted values.
负二项分布计算器
计算第 r 次成功前恰好失败 k 次的概率,支持累积选项,并给出均值和方差。
Normal Approximation to Binomial Calculator
Approximate binomial probabilities P(X ≤ k), P(X ≥ k), or P(X = k) using the normal distribution with continuity correction.
正态分布概率计算器
将 z 分数转换为面积或反向转换,并求任意正态曲线的 P(X<x)、P(X>x) 或区间概率。
Odds Calculator
Convert between probability, decimal odds, fractional odds, and American/moneyline odds in one step.
赔率与概率转换器
将赔率转换为概率,或将概率转换为正反赔率,并提供清晰的可视化分布。
单比例 z 检验计算器
使用 z 检验判断样本比例是否与假设比例存在显著差异。
单样本 t 检验计算器
使用单样本 t 检验判断样本均值是否与假设值存在显著差异。
单因素方差分析计算器
使用单因素方差分析 F 检验比较三个或更多组的均值。
OR Probability Calculator
Calculate P(A or B) — the probability that at least one of two events occurs — for independent or mutually exclusive events.
Order From Least to Greatest Calculator
Arrange any list of numbers — including fractions like 1/2 and 3/4 — from least to greatest, and show their positions on a number line.
Ordering Decimals Calculator
Sort a list of decimal numbers from smallest to largest and see them aligned by decimal place — useful for comparing prices, measurements or test scores.
Ordering Numbers Calculator
Sort any list of numbers in ascending or descending order and assign a rank to each value — tied numbers receive an average rank automatically.
Outlier Calculator
Detect outliers in a data set using the Z-score method — flag any value more than k standard deviations from the mean.
p-hat Calculator
Calculate p-hat (sample proportion), standard error, margin of error, and confidence interval for a proportion.
P 值计算器
将 z、t、卡方或 F 检验统计量转换为任意尾部的 p 值。
配对 t 检验计算器
使用配对 t 检验检验配对/前后测量之间的均值差异。
Parrondo's Paradox Calculator
Explore Parrondo's paradox: calculate the expected gain per step of two individually losing games and their winning alternating combination.
Password Combination Calculator
Calculate the total number of possible password combinations, entropy in bits, and estimated brute-force crack time.
Pearson Correlation Calculator
Compute the Pearson correlation coefficient r between two variables with step-by-step working, r², t-statistic, and significance test at α = 0.05.
百分位数计算器
使用线性插值求任意数据集的百分位数值。免费的在线百分位数计算器,对你的数字进行排序并返回任意所选百分位数处的值。
Percentile Rank Calculator
Find the percentile rank of a score in a dataset — what percentage of values fall at or below it. Uses the (L + 0.5E) / N formula.
排列与组合计算器
为任意 n 和 r 计算排列数 (nPr) 和组合数 (nCr)。免费的在线排列组合计算器,使用阶乘,即时给出结果。
Pie Chart Angle Calculator
Find the central angle of a pie chart slice in degrees — enter the slice value and the total, and get the sector angle and percentage share.
Pie Chart Calculator
Enter comma-separated values and labels to instantly calculate the percentage and degree angle for each slice of a pie chart.
Pie Chart Percentage Calculator
Convert a pie chart sector angle (in degrees) to a percentage share — enter the angle and get the percentage, radians, and remainder.
Point Estimate Calculator
Calculate the point estimate (sample mean), standard error, margin of error and confidence interval for a population mean.
泊松分布计算器
在给定平均速率 lambda 下,计算恰好、至多或至少发生 k 次事件的泊松概率。
Polynomial Regression Calculator
Fit a polynomial curve of any degree (1–5) to your data using least-squares regression and compute R² and RMSE.
Population Variance Calculator
Calculate population variance (σ²), population standard deviation (σ), and sample variance (s²) from a list of numbers.
Possible Combinations Calculator
Calculate the number of possible combinations when choosing r items from n — without replacement (standard nCr) or with replacement (repetition allowed).
Post-Test Probability Calculator
Convert pre-test probability to post-test probability using sensitivity, specificity and the likelihood ratio. Works for positive and negative test results.
概率计算器
计算两个独立事件的概率:P(A and B)、P(A or B) 以及补事件 P(not A)。免费的在线概率计算器,适用于单一和组合事件。
Probability Fraction Calculator
Convert favorable and total outcomes into a probability fraction, percentage, and odds — with complement and odds-for display.
Process Capability Index Calculator
Calculate Cp and Cpk process capability indices from specification limits, process mean and standard deviation. Includes sigma level and out-of-spec estimate.
Quadratic Regression Calculator
Fit a least-squares parabola y = cx² + bx + a to your data. Outputs R², all 3 coefficients, the equation and an optional prediction.
Quartic Regression Calculator
Fit a degree-4 polynomial y = ex⁴ + dx³ + cx² + bx + a to your data using least-squares regression. Shows R², all 5 coefficients and a prediction.
Quartile Calculator
Find Q1, Q2 (median), Q3, IQR and Tukey outlier fences for any data set — with a normal-distribution visualization and five-number summary.
Range Calculator
Calculate the statistical range of a data set — the difference between the maximum and minimum values — plus mid-range and mean.
Raw Score Calculator
Convert a z-score back to the original raw score using x = μ + z·σ. Enter the z-score, mean and standard deviation to get the raw value and percentile.
Rayleigh Distribution Calculator
Calculate the PDF, CDF, mean, mode, median and variance of the Rayleigh distribution for a given scale parameter σ and value x.
Relative Error Calculator
Calculate the relative error and percent error between a measured value and a true (accepted) value, plus accuracy category.
Relative Frequency Calculator
Calculate the relative frequency of an event as a proportion and percentage of total observations, plus the complement.
Relative Risk Calculator
Calculate Relative Risk (RR), Absolute Risk Difference and a 95% confidence interval from two event-rate percentages.
Residual Calculator
Calculate residuals (observed − predicted) for a set of data points. Get RSS, MSE, RMSE and a residual plot to diagnose model fit.
Risk Calculator
Calculate Relative Risk (RR), Odds Ratio (OR), Absolute Risk Difference and Number Needed to Treat/Harm from a 2×2 contingency table.
Roulette Payout Calculator
Calculate roulette payouts, win probability and house edge for any bet type on American (38-pocket) or European (37-pocket) wheels.
RSE Calculator
Calculate Relative Standard Error (RSE = SE / Mean × 100%) to assess the reliability of a survey or sample estimate.
均值样本量计算器
求在目标误差幅度内估计总体均值所需的样本量。
比例样本量计算器
计算在目标误差幅度内估计比例所需的样本量。
Sampling Distribution of the Sample Proportion
Calculate the standard error, margin of error and confidence interval for a sample proportion using the normal approximation.
Sampling Error Calculator
Calculate the sampling error (margin of error) for a proportion survey and find the sample size needed for ±3% or ±5% precision.
SDI Calculator
Calculate Simpson's Diversity Index (D) plus Shannon entropy and Pielou's evenness from species or category counts.
Sensitivity and Specificity Calculator
Calculate sensitivity, specificity, PPV, NPV, accuracy, F1, likelihood ratios and Youden's J from a 2×2 confusion matrix.
Sensitivity Calculator
Calculate diagnostic sensitivity (recall / true positive rate): TP ÷ (TP + FN). Also shows the miss rate (false negative rate).
Shannon Entropy Calculator
Calculate Shannon entropy H from a probability distribution — in bits, nats or hartleys — with maximum entropy and efficiency for any number of outcomes.
Simpson's Diversity Index Calculator
Compute Simpson's Diversity Index (D), Shannon entropy, Pielou's evenness, and Berger–Parker dominance from species counts.
Skewness Calculator
Compute sample or population skewness of a dataset using the Fisher-Pearson coefficient, plus Pearson median skewness and excess kurtosis.
Spearman's Rank Correlation Calculator
Compute Spearman's rank correlation coefficient rₛ for paired data — handles ties using average ranks.
Specificity Calculator
Calculate test specificity (true negative rate) and false positive rate from true negatives and false positives.
标准差计算器
即时计算任意数据集的总体和样本标准差、方差和均值。免费的在线标准差计算器,提供分步结果。
标准误差计算器
从数据列表或样本标准差与样本量计算均值标准误差(SEM)。
Statistical Power Analysis Calculator
Calculate required sample size or statistical power for a two-sample test. Uses Cohen's d, significance level α, and the z-approximation.
Stem-and-Leaf Plot Calculator
Build a stem-and-leaf plot from your data set and get the five-number summary instantly.
Sum of Squares Calculator
Compute the sum of squared deviations SS = Σ(xᵢ − x̄)² plus sample and population variance and standard deviation from any list of numbers.
t-Statistic Calculator
Compute the one-sample t-statistic, degrees of freedom, standard error, and two-tailed p-value from sample mean, standard deviation, and sample size.
Third Quartile Calculator
Calculate Q3 (the third quartile / 75th percentile) for any data set using the Tukey hinges method, with the five-number summary and IQR.
Two Envelopes Paradox Calculator
Explore the two-envelopes paradox: calculate the expected value of switching vs keeping your envelope and find the break-even probability for switching.
双比例 z 检验计算器
使用合并双比例 z 检验比较两个独立样本的比例。
双样本 t 检验计算器
使用 Welch 或合并双样本 t 检验比较两个独立组的均值。
均匀分布计算器
计算 [a,b] 上的连续均匀概率:即时求出 P(c<X<d)、均值和方差。
并集、交集与补集计算器
为两个事件计算补集、并集和交集概率,可选独立或提供联合概率。
Upper and Lower Fence Calculator
Calculate both Tukey fences (upper: Q3 + k × IQR, lower: Q1 − k × IQR) to find outlier thresholds for any data set.
Upper Control Limit Calculator
Calculate the Upper Control Limit (UCL) and Lower Control Limit (LCL) for a Shewhart control chart using the process mean and sigma.
Upper Fence Calculator
Calculate the upper Tukey fence (Q3 + k × IQR) from Q1 and Q3 to identify potential high outliers in a data set.
Variance Calculator
Calculate sample variance, population variance, standard deviation, coefficient of variation, and standard error from any numeric data set.
Venn Diagram Calculator
Calculate union, intersection, A-only, B-only, and conditional probabilities for two overlapping sets with a Venn diagram breakdown.
Weibull Distribution Calculator
Calculate Weibull PDF, CDF, survival probability, mean, median, mode, and variance from shape k and scale λ.
加权平均值计算器
根据数值和权重对计算加权平均值(加权均值)。免费的在线加权平均值计算器,适用于成绩、GPA、价格和调查数据。
Wilcoxon Rank Sum Test Calculator (Mann-Whitney U)
Run a non-parametric Wilcoxon rank sum / Mann-Whitney U test to compare two independent groups without assuming normality.
Youden's J Index Calculator
Calculate Youden's J statistic to measure a diagnostic test's overall discriminatory ability from sensitivity and specificity.
Z 分数计算器
根据均值和标准差计算一个值的 z 分数(标准分)。免费的在线 z 分数计算器,显示一个点距离均值有多少个标准差。
Σm·P(x) Calculator
Calculate the mean x̄ = Σ m·p(x), variance, and standard deviation from a grouped frequency distribution using class midpoints.
三维距离计算器
计算三维空间中两点之间的直线距离、中点及各轴差值。
环形面积计算器
根据外径和内径计算环形(圆环)的面积、宽度及周长。
弧长与弦长计算器
根据半径和圆心角计算圆弧的弧长、弦长及矢高。
圆形计算器
根据半径计算圆的面积、周长和直径。
扇形计算器
根据半径和圆心角计算圆扇形的面积、弧长和周长。
弓形计算器
根据半径和圆心角计算圆弓形的面积、弦长、弧长和矢高。
外接圆半径与内切圆半径计算器
根据三角形的三条边长计算其外接圆半径和内切圆半径。
圆锥计算器
根据底面半径和高计算正圆锥的体积、斜高和表面积。
圆台计算器
计算圆台(截锥体)的体积、斜高和各类表面积。
立方体计算器
使用精确公式根据单一棱长计算立方体的体积、表面积和体对角线。
圆柱计算器
使用含 π 的精确公式根据半径和高计算圆柱的体积和表面积。
椭圆计算器
使用拉马努金公式根据半长轴和半短轴计算椭圆的面积和近似周长。
椭圆周长计算器
用拉马努金公式估算椭圆周长,并计算其面积和离心率。
椭球体积计算器
根据三个半轴求椭球的体积和近似表面积。
黄金比例计算器
按黄金比例 φ 分割一段长度,或缩放一段已知线段以求两个黄金分割部分。
海伦公式计算器
用海伦公式根据三角形三边长度求其面积。
六棱柱计算器
求正六棱柱的体积、侧面积和全面积。
平行四边形计算器
根据平行四边形的底、垂直高度和边长计算其面积和周长。
坐标多边形面积计算器
使用鞋带公式根据顶点坐标计算任意多边形的面积、周长和质心。
棱锥计算器
根据正四棱锥的底边和高计算其体积、斜高和表面积。
矩形计算器
使用精确公式根据矩形的长和宽即时计算其面积、周长和对角线。
正八面体计算器
根据棱长计算正八面体的体积、表面积、高度和内外接球半径。
正多边形计算器
根据边数和边长求任意正多边形的面积、周长、内外角、垂心距和外接圆半径。
正四面体计算器
求正四面体的体积、表面积、高度及内切球和外接球半径。
菱形计算器
使用精确的几何公式根据菱形的两条对角线计算其面积、边长和周长。
球体计算器
使用含 π 的精确公式根据球的半径计算其体积、表面积和直径。
球冠计算器
计算球冠(穹顶)的体积、曲面面积和底圆半径。
正方形计算器
使用精确的几何公式根据单一边长计算正方形的面积、周长和对角线。
圆环体计算器
根据两个半径计算圆环体(甜甜圈形状)的体积、表面积和直径。
梯形面积计算器
根据梯形的两条平行边以及它们之间的垂直高度计算梯形的面积。
三角形面积计算器
根据三角形的底和高,或使用海伦公式根据三条边长求出三角形的面积,以及周长。
12V Wire Size Calculator
Find the correct AWG copper wire gauge for a 12 V DC circuit based on current, wire length, and acceptable voltage drop.
220V Wire Size Calculator
Find the correct AWG copper wire gauge for 220 V / 230 V / 240 V circuits based on current, run length, and allowed voltage drop.
24V Wire Size Calculator
Find the correct AWG copper wire gauge for a 24 V DC circuit based on current, one-way wire length, and acceptable voltage drop.
3-Phase Motor Amperage Calculator
Calculate the full-load line current of a 3-phase AC motor from its rated kW, supply voltage, power factor and efficiency.
绝对星等与视星等计算器
转换任意恒星的视星等、绝对星等与距离之间的关系。
Absolute Humidity Calculator
Convert air temperature and relative humidity into absolute humidity (g/m³), dew point and saturation vapour pressure.
AC Wattage Calculator
Calculate real power (W), apparent power (VA) and reactive power (VAR) for single- or three-phase AC circuits from voltage, current and power factor.
加速度计算器
使用 a = (vf − vi) / t 根据一段时间内速度的变化计算加速度。以 m/s² 和 g 的倍数给出结果。
Acceleration Calculator
Calculate acceleration from net force and mass using Newton's second law: a = F ÷ m, with results in m/s² and g-units.
Acceleration Due to Gravity Calculator
Calculate gravitational acceleration g = GM/r² at the surface or any altitude of Earth, Moon, Mars or any body.
Acceleration of a Particle in an Electric Field Calculator
Calculate the acceleration a = qE/m of a charged particle (proton, electron, ion) in a uniform electric field.
Acoustic Impedance Calculator
Calculate acoustic impedance (Z = ρc) for two media and find the intensity reflection and transmission coefficients at the interface.
Acres Per Hour Calculator
Calculate agricultural field coverage in acres per hour from ground speed, implement width and field efficiency. Also shows hectares/hr and daily acreage.
Activation Energy Calculator
Calculate activation energy Ea from two rate constants at two temperatures using the two-point Arrhenius equation.
Activity Coefficient Calculator
Calculate the mean ionic activity coefficient γ± for electrolyte solutions using the Debye–Hückel limiting law or the Davies equation.
Actual Yield Calculator
Calculate percent yield from actual and theoretical yield — a core chemistry lab calculation for reaction efficiency.
AI Water Footprint Calculator
Estimate the water consumed by your AI queries. Based on 2023 research: a GPT-4-class prompt uses ~50 mL of data-centre cooling water.
Air Density Calculator
Calculate moist air density (kg/m³) from temperature, atmospheric pressure and relative humidity using the ideal-gas law and Magnus formula.
Air Pressure at Altitude Calculator
Calculate atmospheric pressure, temperature, and air density at any altitude using the International Standard Atmosphere (ISA) model.
Air-Fuel Ratio (AFR) Calculator
Calculate the air-fuel ratio (AFR) and lambda (λ) for any fuel — see whether the mixture is rich, lean or stoichiometric.
Alfvén Velocity Calculator
Calculate the Alfvén velocity in a magnetized plasma from the magnetic field strength B and plasma mass density ρ.
Alien Civilization Calculator
Estimate the number of technologically communicating extraterrestrial civilizations in the Milky Way using the Drake Equation.
Allele Frequency Calculator
Calculate allele and genotype frequencies (p², 2pq, q²) for a two-allele locus under Hardy–Weinberg equilibrium.
Alligation Calculator
Use the alligation alternate method to find the volumes of two solutions needed to produce a mixture at a desired concentration.
Altitude Temperature Calculator
Calculate air temperature, pressure and density at any altitude using the International Standard Atmosphere (ISA) model up to 32,000 m.
Amp to Wire Size Calculator
Find the minimum AWG or kcmil wire size for a given amperage load using NEC 2020 Table 310.15(B)(16) ampacity values for copper or aluminum conductors.
Angle of Incidence Calculator
Calculate the angle of incidence from source height and horizontal offset, plus reflected angle and grazing angle for any flat surface.
Angle of Refraction Calculator
Calculate the angle of refraction using Snell's law for any two media, with total internal reflection check and critical angle.
Angle of Repose Calculator
Calculate the angle of repose for sand, gravel, soil and other granular materials from the coefficient of static friction.
Angle of Twist Calculator
Calculate the torsional angle of twist for solid and hollow circular shafts using the formula φ = TL/(GJ), with max shear stress.
Angular Acceleration Calculator
Calculate angular acceleration (α) in rad/s² from Δω/t, net torque and moment of inertia, or tangential acceleration and radius.
Angular Displacement Calculator
Calculate angular displacement θ in radians, degrees and revolutions from arc length/radius, kinematic equations, or average angular velocity.
Angular Frequency Calculator
Calculate angular frequency ω (rad/s) from period, ordinary frequency, a spring–mass system, or a simple pendulum length.
Angular Momentum Calculator
Calculate angular momentum (L) in kg·m²/s from I·ω, shape/mass/radius, or point-mass orbital motion m·v·r.
Angular Resolution Calculator
Calculate minimum resolvable angle for telescopes (Rayleigh criterion, Dawes' limit) or minimum detail for microscopes (Abbe limit).
角直径计算器(小角度公式)
由天体的真实尺寸和距离计算其角直径,或求解其中任一量。
角速度计算器
由周期、频率或线速度计算 rad/s 和 RPM 下的角速度。
Animal Mortality Rate Calculator
Calculate crude and annual mortality rates, survival rate, and deaths per 1,000 for any animal population study.
Annealing Temperature Calculator
Calculate PCR primer melting temperature (Tm) and annealing temperature from base composition using Wallace rule or empirical formula.
Aperture Area Calculator
Calculate the physical aperture area of a circular lens, mirror, or camera from its diameter or focal length and f-number.
API Gravity Calculator
Convert between API gravity (°API) and specific gravity for petroleum liquids. Classifies crude as extra-heavy, heavy, medium, light, or very light.
Archimedes' Principle Calculator
Calculate the buoyant (upthrust) force on a submerged object using Archimedes' principle: F = ρ × V × g.
Arrhenius 方程计算器
使用 Arrhenius 方程及其双温度形式计算活化能或速率常数。
Arrow Speed Calculator
Calculate arrow speed (fps & m/s), kinetic energy and momentum from draw weight, draw length, arrow weight and bow efficiency.
Atom Calculator
Find the number of protons, neutrons and electrons in any atom or ion, plus nuclear binding energy from the Bethe-Weizsäcker formula.
Atom Economy Calculator
Calculate atom economy for any reaction: the percentage of reactant atoms that end up in the desired product versus waste by-products.
Atomic Mass Calculator
Calculate the weighted average atomic mass of an element from its isotope masses and natural abundances — up to four isotopes.
Attenuation Calculator
Calculate signal attenuation in decibels (dB) from input and output power or amplitude, plus attenuation coefficient and half-power distance.
Average Atomic Mass Calculator
Calculate the average atomic mass of an element from its isotope masses and natural abundances — up to 4 isotopes supported.
Avogadro's Number Calculator
Convert between moles, number of particles and mass using Avogadro's constant (6.022 × 10²³). Covers atoms, molecules and formula units.
Bacteria Growth Calculator
Calculate bacterial population after any elapsed time using the exponential doubling formula N = N₀ × 2^(t/g), with growth rate constant and fold increase.
Ballistic Coefficient Calculator
Calculate the G1 ballistic coefficient (BC) and sectional density of a bullet from its mass in grains, diameter, and form factor.
Bank Angle Calculator
Calculate the ideal bank angle for a vehicle or aircraft in a circular turn — eliminates lateral slip at any speed and radius.
Barn-Pole Paradox Calculator
Explore the barn-pole (ladder) paradox of special relativity: compute Lorentz contraction in each reference frame and the simultaneity shift that resolves the contradiction.
Basal Area Calculator
Calculate tree basal area (m²) from diameter at breast height (DBH) and stand basal area per hectare for forestry surveys.
Beat Frequency Calculator
Calculate the beat frequency and beat period when two close-frequency sound waves interfere. Shows the amplitude envelope with the number of beats per second.
Beer–Lambert Law Calculator
Solve the Beer–Lambert law A = ε·c·l for absorbance, concentration, molar absorptivity, or path length with transmittance output.
Belt Length Calculator
Calculate the exact length of an open or crossed drive belt from the two pulley diameters and centre distance, with wrap angles and speed ratio.
Bend Allowance Calculator
Calculate bend allowance, bend deduction and outside set-back for sheet metal fabrication using the standard K-factor formula.
Benzo[a]Pyrene Cancer Risk Calculator
Estimate excess lifetime cancer risk from benzo[a]pyrene (B[a]P) in air using the WHO inhalation unit risk factor.
Bernoulli's Equation Calculator
Calculate downstream pressure P₂ using Bernoulli's equation. Enter upstream pressure, velocities, elevations and fluid density.
Binoculars Range Calculator
Calculate how far binoculars can identify a target, plus exit pupil, relative brightness and twilight factor for any magnification and objective lens.
Biot Number Calculator
Calculate the Biot number (Bi = h·Lc/k) and check whether lumped capacitance is valid for transient heat transfer analysis.
Bird Age Calculator
Convert your bird's age to a human-equivalent age using the proportional lifespan method for 10 common pet bird species.
Black Hole Calculator
Calculate a black hole's Schwarzschild radius, event horizon area, photon sphere and ISCO from its mass in solar masses.
Black Hole Temperature Calculator
Calculate the Hawking temperature, luminosity and evaporation time of a black hole of any mass using CODATA 2018 constants.
Blackbody Radiation Calculator
Calculate peak wavelength, radiated intensity and total power for a blackbody using Wien's displacement law and the Stefan-Boltzmann equation.
Blast Radius Calculator
Estimate fireball and blast damage zone radii for a nuclear weapon yield using Glasstone cube-root scaling. Educational reference only.
Bleach Dilution Calculator
Calculate how much bleach and water to mix to reach a target sodium hypochlorite concentration using the dilution formula C₁V₁ = C₂V₂.
BMEP Calculator
Calculate Brake Mean Effective Pressure from engine torque and displacement for 4-stroke or 2-stroke engines, with power output.
Bohr 模型能级计算器
用 Bohr 模型计算类氢原子的能级、轨道半径以及跃迁光子能量。
Boiling Point at Altitude Calculator
Calculate the boiling point of water at any altitude (0–11 000 m) using the ISA atmosphere and Clausius–Clapeyron equation.
Boiling Point Calculator
Calculate the boiling point of water, ethanol, acetone and other common substances at any pressure using the Clausius–Clapeyron equation.
Boiling Point Elevation Calculator
Calculate how much a dissolved solute raises the boiling point of a solvent using ΔTb = Kb × m × i (colligative property).
Boltzmann Factor Calculator
Calculate the Boltzmann factor exp(−E/kT) and thermal energy kT for any energy barrier and temperature — fundamental to thermodynamics, kinetics and statistical mechanics.
键能反应焓计算器
由断键与成键的键焓估算反应焓。
Bond Order Calculator
Calculate bond order from bonding and antibonding molecular orbital electron counts using MO theory.
Books vs E-books Calculator
Compare the lifetime CO₂ footprint of reading physical books versus an e-reader — find the break-even point where the e-reader wins.
Boost Converter Calculator
Calculate duty cycle, input current, power loss and efficiency for a boost (step-up) DC–DC converter from V_in, V_out, load current and efficiency.
Boyle's Law Calculator
Calculate the unknown pressure or volume using Boyle's Law P₁V₁ = P₂V₂. Enter any three of the four values.
Bragg's Law Calculator
Solve Bragg's law (nλ = 2d·sin θ) for X-ray wavelength, interplanar spacing, or Bragg angle from any two known values.
Breaker Size Calculator
Calculate the correct circuit breaker ampere rating for any electrical load using NEC 80% continuous-load rule and standard breaker sizes.
Brewster's Angle Calculator
Calculate Brewster's angle for any two optical media using their refractive indices — with refracted ray angle, reflectance, and an interactive n₂/n₁ plot.
Bridge Rectifier Calculator
Calculate the DC output voltage, ripple, PIV and efficiency of a full-wave bridge rectifier from AC input voltage and diode parameters.
Brinell Hardness Number (BHN) Calculator
Calculate the Brinell Hardness Number (HB) from the applied load, ball indenter diameter and measured indentation diameter using the ISO 6506 formula.
Broad-Crested Weir Flow Calculator
Calculate the discharge over a broad-crested weir using the standard hydraulic formula Q = Cd × 1.705 × L × H^(3/2), with critical depth and velocity.
BTU to Tons of Refrigeration Converter
Convert between BTU/hr, tons of refrigeration, kilowatts, watts and kcal/hr for HVAC and refrigeration capacity. 1 ton = 12,000 BTU/hr = 3.517 kW.
Buck Converter Calculator
Calculate output voltage, power loss, and minimum inductance for a step-down (buck) DC-DC converter from duty cycle and switching frequency.
Buckling Calculator
Calculate the Euler critical buckling load for a slender column given Young's modulus, moment of inertia, length, and end conditions.
Buffer Capacity Calculator
Calculate the Van Slyke buffer capacity β (mol/L per pH unit) for a weak acid/base buffer at a given pH, pKa, and total concentration.
Buffer pH Calculator
Compute the pH of a weak acid/conjugate base buffer using the Henderson–Hasselbalch equation from pKa and component concentrations.
Bug-Rivet Paradox Calculator
Explore the special-relativity bug-rivet paradox: compute Lorentz contraction and see how length and simultaneity differ between inertial frames.
Bulb Spacing Calculator
Calculate how many flower bulbs fit in a rectangular planting bed at a chosen centre-to-centre spacing — rows, columns and total count.
Bulk Modulus Calculator
Calculate the bulk modulus K and compressibility β of a material from the applied pressure change and volumetric strain.
Bullet Energy Calculator
Calculate the muzzle energy of a bullet in joules and ft·lbf from its mass and velocity, plus momentum and IPSC power factor.
Buoyancy Calculator
Calculate the buoyant force on a submerged object using Archimedes' principle: F = ρ × V × g.
Buoyancy Experiment Calculator
Determine buoyant force, displaced volume, and object density from a spring-scale experiment: weigh in air, then in fluid.
Buoyant Force Calculator
Calculate buoyant force, object weight, and net force to determine whether an object floats or sinks in a fluid.
Calibration Curve Calculator
Fit a linear calibration curve (y = mx + b) to standard concentration–response data and determine unknown sample concentrations.
量热热量计算器(q = mcΔT)
由质量、比热容和温度变化,用 q = mcΔT 计算吸收或释放的热量。
Capacitance Calculator
Calculate the capacitance of a parallel plate capacitor using C = ε₀εᵣA/d, plus stored charge and energy for a given voltage.
Capacitive Reactance Calculator
Calculate capacitive reactance Xc from frequency and capacitance, with optional RMS current and reactive power for AC circuit analysis.
Capacitive Transformerless Power Supply Calculator
Calculate capacitive reactance, load current and output power for a mains-connected capacitor dropper (transformerless) power supply.
Capacitor Calculator
Calculate stored charge, stored energy and capacitive reactance from capacitance, voltage and frequency.
Capacitor Charge Time Calculator
Calculate how long an RC circuit takes to charge a capacitor to any target voltage using the time constant τ = RC.
电容器能量与电荷计算器
由电容和施加电压求电容器存储的电荷量和能量。
Capacitor Size Calculator
Find the capacitance you need from stored energy, stored charge, power-supply ripple, or a target capacitive reactance.
串并联电容器计算器
由一组电容值求电容器串联和并联的总电容。
Capacitors in Series Calculator
Calculate the equivalent capacitance of any number of capacitors connected in series — result is always less than the smallest capacitor.
Car Center of Mass Calculator
Find a car's longitudinal centre of gravity from front and rear axle loads and wheelbase, and calculate the front/rear weight distribution.
Car Crash Force Calculator
Calculate the impact force, g-force and kinetic energy in a car crash from vehicle mass, speed and stopping distance.
Car Jump Distance Calculator
Calculate how far a car travels through the air after launching off a ramp: jump distance, air time and peak height using projectile motion.
Car vs Bike Commute Calculator
Compare the annual cost, CO₂ emissions and commute time of driving a car versus cycling for your daily commute.
Carbon Dating Calculator
Calculate the radiocarbon age of a sample from its remaining C-14 fraction using the radioactive decay equation.
Carburetor CFM Calculator
Calculate the carburetor CFM rating for a 4-stroke engine from displacement, peak RPM and volumetric efficiency.
卡诺效率计算器
由热源和冷源温度求热机的最大理论效率。
Carrying Capacity Calculator
Calculate population size at any time using the logistic growth model — enter carrying capacity K, initial population, intrinsic growth rate and time.
Cat Age Calculator
Convert your cat's age to the equivalent human age using the AAFP non-linear feline age conversion scale.
Cat BMI Calculator
Assess your cat's weight by comparing it to the vet-set ideal — rated on the 1–9 Body Condition Score (BCS) scale.
Cat Calorie Calculator
Calculate how many calories your cat needs per day using the veterinary RER formula, adjusted for life stage and activity level.
Cat Pregnancy Calculator
Calculate days remaining to your cat's due date, track weekly gestation progress, and see key developmental milestones.
Cat Quality of Life Calculator
Score your cat's quality of life using the veterinary HHHHHMM scale (Hurt, Hunger, Hydration, Hygiene, Happiness, Mobility, More). Total ≥ 35/70 indicates acceptable QoL.
Cattle Per Acre Calculator
Calculate how many cattle an acre of pasture can support using forage yield, utilization rate and grazing season length.
Cell Dilution Calculator
Calculate cell dilutions using C₁V₁ = C₂V₂ — find final volume, final concentration, stock volume or initial concentration from any three values.
Cell Doubling Time Calculator
Calculate cell population doubling time and growth rate from initial count, final count and elapsed time. For cell culture and microbiology.
Centrifugal Force Calculator
Calculate centrifugal (centripetal) force, g-force, and linear velocity for a rotating object from mass, radius and RPM or angular velocity.
Centrifuge Speed Calculator
Convert centrifuge speed between RPM and RCF (relative centrifugal force) using rotor radius. Find RPM for a target g-force.
向心加速度计算器
由速度和半径计算向心(径向)加速度,a=v²/r=ω²r。
向心力计算器
圆周运动的向心力,F=mv²/r,并输出加速度。
Charles's Law Calculator
Apply Charles's Law (V₁/T₁ = V₂/T₂) to find the final volume or temperature of a gas at constant pressure. Temperatures converted to Kelvin automatically.
Chemical Equation Balancer Calculator
Automatically balance a chemical equation by entering element symbols — uses matrix Gaussian elimination to find the smallest integer stoichiometric coefficients.
Chemical Name Calculator
Generate the IUPAC name and formula for binary ionic or covalent compounds by selecting two elements and their subscripts.
Chemical Oxygen Demand (COD) Calculator
Calculate COD in mg/L from dichromate back-titration results using Standard Method 5220C (FAS blank and sample volumes, normality, sample size).
Cigarette Butts Calculator
Estimate the number, weight, and volume of cigarette butts discarded by a group of smokers over any time period.
Circular Motion Calculator
Calculate linear velocity, angular velocity, frequency, centripetal acceleration and centripetal force for uniform circular motion.
Cloud Base Calculator
Estimate cumulus cloud base height (lifted condensation level) from surface temperature and dew point using the standard 400-ft rule.
CO₂ Breathing Emission Calculator
Calculate how much CO₂ a person exhales per breath, minute, hour, day and year from breathing rate and tidal volume.
CO₂ Grow Room Calculator
Calculate how much CO₂ you need to add to a grow room to reach a target ppm from ambient levels.
Coefficient of Discharge Calculator (Cd)
Calculate the coefficient of discharge Cd = Q_actual / Q_theoretical for an orifice using Torricelli's theorem.
Coefficient of Performance (COP) Calculator
Calculate the COP for a refrigerator or heat pump and compare it to the theoretical Carnot maximum using cold-side heat, work input, and reservoir temperatures.
Combustion Analysis Calculator
Determine the empirical formula of an organic compound from combustion analysis data: CO₂, H₂O, N₂, and SO₂ masses.
Combustion Reaction Calculator
Balance the complete combustion equation for any hydrocarbon (CₙHₘ) and calculate masses of CO₂, H₂O, and O₂ from a given fuel mass.
Compost Calculator
Calculate the carbon-to-nitrogen (C:N) ratio of your compost pile and learn if you need more browns or greens.
Compressibility Calculator
Calculate volumetric compressibility (κ) and bulk modulus from initial volume, final volume, and applied pressure.
Compton Scattering Calculator
Calculate the Compton wavelength shift, scattered photon wavelength, and electron recoil energy for any photon wavelength and scattering angle.
Compton Wavelength Calculator
Calculate the Compton wavelength and reduced Compton wavelength of the electron, proton, neutron, muon, or tau particle.
Concentration Calculator
Calculate solution molarity (mol/L) from the mass of solute, molar mass, and volume of solution. Also shows mass concentration and mole amount.
Conductivity to Resistivity Calculator
Convert electrical conductivity (S/m) to resistivity (Ω·m) using ρ = 1/σ, with unit conversions to Ω·cm, μΩ·m, mS/m and S/cm.
Conservation of Momentum Calculator
Calculate final velocities for elastic or perfectly inelastic 1D collisions using conservation of momentum. Energy loss shown for inelastic case.
Contact Lens Vertex Distance Calculator
Convert spectacle prescription to contact lens power using the vertex distance formula Vc = Vs / (1 − d·Vs). Rounds to nearest 0.25 D.
Copper Wire Weight Calculator
Calculate the weight of solid copper wire by diameter (mm) or AWG gauge and length. Includes cross-section area and DC resistance.
Coriolis Effect Calculator
Calculate the Coriolis acceleration and force on a moving object at any latitude on Earth.
Corn Yield Calculator
Estimate corn (maize) yield in bushels per acre using the yield component method: plant population, ears, and kernels.
Cost of Owning a Dog Calculator
Estimate the annual and lifetime cost of owning a dog — food, vet, grooming, insurance, boarding, and more.
库仑定律计算器
由电荷量大小和间距,用库仑定律求两点电荷间的静电力。
COVID Lockdown Pollution Calculator
Estimate how much NO₂, PM2.5 and CO₂ emissions fell during COVID-19 lockdowns based on traffic and industrial activity reduction.
Cow Gestation Calculator
Calculate expected calving date and gestation progress for cattle. Supports 9 breed-specific gestation lengths from 278 to 292 days.
Crawl Ratio Calculator
Calculate the crawl ratio of any 4WD vehicle from transmission, transfer case and axle ratios. Includes ground speed at idle and off-road capability rating.
Cricket Chirp Thermometer Calculator
Estimate temperature from cricket chirp rate using Dolbear's Law — count chirps per minute and convert to °F, °C and K.
临界角(全内反射)计算器
由两种介质的折射率求全内反射的临界角。
Critical Damping Calculator
Calculate the damping ratio, critical damping coefficient, natural frequency, and step response for a spring-mass-damper system.
Crossover Frequency Calculator
Calculate inductor and capacitor values for a 1st- or 2nd-order speaker crossover at any crossover frequency and speaker impedance.
Crude Protein Calculator
Calculate crude protein content (%) from nitrogen (%) using the Jones conversion factor — supports food, feed and agronomic samples.
Cryptocurrency Carbon Footprint Calculator
Estimate the energy use (kWh) and CO₂ emissions of cryptocurrency transactions — Bitcoin, Ethereum, and more — with editable 2024 estimates.
Cube Density Calculator
Calculate the density of a cube from its mass and side length. Get density in g/cm³, kg/m³ and lb/ft³ with unit conversion.
Cubic Unit Cell Calculator
Calculate atomic radius, packing efficiency, atoms per cell and coordination number for simple cubic, BCC and FCC crystal structures.
Curie Constant Calculator
Calculate the Curie constant, effective magnetic moment, and molar susceptibility for a paramagnetic material given the g-factor, J, and temperature.
Curie's Law Calculator
Calculate the magnetic susceptibility and magnetization of a paramagnetic material with Curie's law χ = C/T.
Current Divider Calculator
Find how current splits across two parallel resistors: I₁ = I × R₂/(R₁+R₂) and I₂ = I × R₁/(R₁+R₂).
Cutoff Frequency Calculator
Calculate the cutoff (−3 dB) frequency for RC, RL, and LC passive filters from component values.
Cv Flow Calculator
Calculate valve flow coefficient (Cv or Kv) from flow rate, pressure drop, and specific gravity — or solve for any unknown.
Cyclotron Frequency Calculator
Calculate cyclotron frequency, angular frequency and orbital period for a charged particle in a uniform magnetic field using f = qB / (2πm).
Cylinder Density Calculator
Calculate the density of a cylindrical object from its mass, radius and height — outputs g/cm³, kg/m³, volume and surface area.
Daily Light Integral (DLI) Calculator
Calculate DLI (mol/m²/day) from PPFD and photoperiod. See how much light plants receive daily and whether it meets crop requirements.
Damping Ratio Calculator
Calculate the damping ratio ζ, critical damping, natural frequency and free-vibration response of a spring-mass-damper system.
Darcy Friction Factor Calculator
Calculate the Darcy–Weisbach friction factor for pipe flow from Reynolds number, pipe diameter, and wall roughness (Swamee–Jain method).
Darcy-Weisbach Calculator
Calculate pipe pressure drop (ΔP) and head loss using the Darcy-Weisbach equation with the Swamee-Jain friction factor. Covers laminar and turbulent flow.
Darcy's Law Calculator
Calculate porous-media flow rate with Darcy's law: Q = K × A × (Δh / L). Get volumetric flow, Darcy flux and hydraulic gradient.
Daylight Hours Calculator
Calculate hours of daylight, approximate sunrise and sunset times for any latitude and date — using solar declination and the sunrise hour-angle formula.
dB Calculator
Convert between decibel (dB) gain and power or amplitude ratios. Enter dB to find ratio, or ratio to find dB.
dB Gain Calculator
Calculate decibel (dB) gain or attenuation from input and output voltage, current or power values.
DC Wire Size Calculator
Calculate the minimum wire cross-section (mm²) and AWG gauge for a DC circuit based on current, length and allowable voltage drop.
德布罗意波长计算器
由粒子质量和速度,用 λ = h/(mv) 计算其物质波波长。
Debye Length Calculator
Calculate the Debye screening length in electrolytes and plasmas — the distance over which a point charge's electric field is exponentially suppressed.
分贝与声强级计算器
用 L = 10·log10(I/I0) 将声强转换为分贝,或由分贝级求声强。
Degree of Unsaturation Calculator (IHD / DBE)
Calculate the degree of unsaturation (index of hydrogen deficiency, IHD) for any organic molecular formula — identifies double bonds, triple bonds and rings.
Delta-v Calculator
Calculate a rocket's delta-v from initial mass, dry mass and specific impulse using the Tsiolkovsky rocket equation.
Delta–Wye (Δ–Y) Resistor Converter
Convert resistor networks between Delta (Δ) and Wye (Y / Star) configurations in both directions for circuit analysis.
Density Altitude Calculator
Calculate density altitude from field elevation, altimeter setting and outside air temperature for aviation takeoff and climb performance.
密度计算器
使用 密度 = 质量 / 体积 根据质量和体积计算密度。即时以 kg/m³ 和 g/cm³ 给出固体、液体和气体的结果。
Density Mass Volume Calculator
Calculate density, mass, or volume from any two known values using the triangle formula ρ = m ÷ V.
Density to Mass Calculator
Calculate the mass of an object from its density and volume using m = ρ × V. Results in kg, grams, and tonnes.
密度转摩尔浓度计算器
利用溶质摩尔质量,将溶液密度和质量分数转换为摩尔浓度。
Density to Weight Calculator
Calculate the weight (gravitational force) of an object from its density and volume. Results in Newtons, kgf, and lbf.
Detention Time Calculator
Calculate hydraulic detention time (HRT) for water and wastewater treatment tanks: HDT = Volume ÷ Flow rate.
Dew Point Calculator
Calculate the dew point temperature from air temperature and relative humidity using the August-Roche-Magnus approximation.
Differential Pressure Calculator
Calculate differential pressure (P1 − P2) across any two points with instant conversion to Pa, kPa, bar, psi, mmHg, inH₂O and more.
Diffraction Calculator
Calculate diffraction angles for a grating or single slit using d·sin θ = mλ. Enter wavelength, spacing, and order.
Diffusion Coefficient Calculator
Calculate the diffusion coefficient of a spherical particle in a liquid using the Stokes-Einstein equation D = k_BT/(6πηr).
Dihybrid Cross Punnett Square Calculator
Build a 4×4 dihybrid Punnett square for two genes and get the genotype and phenotype ratios for all 16 offspring combinations.
稀释计算器(M1V1 = M2V2)
利用 M1V1 = M2V2 求解溶液稀释问题,即时找到缺失的浓度或体积。
Dilution Factor Calculator
Calculate the dilution factor, final concentration, and diluent volume using C₁V₁ = C₂V₂. Supports any concentration unit.
Diopter Calculator
Convert between diopters and focal length, and find the image distance for a lens of any optical power.
Dipole Antenna Calculator
Calculate the length of a half-wave dipole antenna from frequency and velocity factor for ham radio, broadcast, and RF work.
Dipole Moment Calculator
Calculate the electric dipole moment from charge and separation distance, in both Debye and SI units (C·m).
Displacement Calculator
Calculate displacement from initial velocity, acceleration, and time using the kinematic equation s = ut + ½at². Also finds final velocity and average velocity.
Distance Attenuation Calculator
Calculate how sound pressure level or light intensity decreases with distance using the inverse square law: L₂ = L₁ + 20·log₁₀(d₁/d₂).
距离模数计算器
在秒差距和光年之间转换距离模数与物理距离(双向转换)。
Distance to Horizon Calculator
Calculate how far the horizon is from an observer at a given height above sea level using the geometric horizon formula.
DNA Concentration Calculator (A260 Spectrophotometry)
Calculate DNA or RNA concentration from A260 absorbance using Beer-Lambert extinction coefficients. Includes A260/A280 purity ratio and total yield.
DNA Copy Number Calculator
Calculate the number of DNA molecules (copies) in a sample from mass in nanograms and fragment length in base pairs.
DNA Ligation Calculator
Calculate the mass of insert DNA needed for a ligation reaction given vector mass, sizes, and the desired insert:vector molar ratio.
DNA to mRNA Calculator
Convert a DNA sequence to its mRNA transcript. Supports template or coding strand input, shows GC content and codon count.
Dog Age Calculator
Convert your dog's age to the human equivalent using a size-based model. More accurate than the popular multiply-by-7 rule.
Dog BMI Calculator
Calculate your dog's body mass index from weight and shoulder height. A rough screening tool — BCS is the clinical standard for dogs.
Dog Calorie Calculator
Calculate your dog's daily calorie needs using the veterinary RER × lifestyle-factor formula. Covers all life stages and activity levels.
Dog Crate Size Calculator
Find the right crate size for your dog by entering its body length and standing height.
Dog Food Calculator
Calculate how much food your dog needs each day based on weight, age, and activity level.
Dog Harness Size Calculator
Find the right harness size for your dog by entering the chest girth circumference.
Dog Heat Cycle Calculator
Predict when your dog will next come into heat and identify the fertile window.
Dog Life Expectancy Calculator
Estimate your dog's life expectancy and human-age equivalent based on breed size class.
Dog Pregnancy Calculator
Calculate your dog's due date and key pregnancy milestones from the mating date.
Dog Quality of Life Calculator
Assess your dog's quality of life using the veterinary HHHHHMM scale. Score seven criteria to get a total out of 70 with an actionable verdict.
Dog Size Calculator
Predict your puppy's adult weight from current age (weeks) and weight using a breed-size growth model. Results within ±20–30 % for most dogs.
多普勒效应计算器
使用多普勒公式计算来自运动声源和观测者的观测频移。
Double Bond Equivalent Calculator (Degrees of Unsaturation)
Calculate the double bond equivalent (DBE / degrees of unsaturation) from a molecular formula: C, H, N, X counts.
Drag Equation Calculator
Calculate aerodynamic drag force using F_D = ½ρv²C_D A — enter velocity, drag coefficient, frontal area and fluid density.
Drake Equation Calculator
Estimate the number of communicating civilizations in the Milky Way using the Drake equation: N = R* × f_p × n_e × f_l × f_i × f_c × L.
漂移速度计算器
根据电流、载流子密度和截面积计算导体中载流子的漂移速度。
Drip Faucet Calculator
Calculate how much water a dripping faucet wastes per day and per year in litres and gallons, plus the annual cost.
Dry Matter Calculator
Calculate dry matter percentage, moisture content and water loss from fresh and dry weight measurements. Essential for agriculture, food science and forage analysis.
E = mc² Calculator
Apply Einstein's E = mc² to any mass in kg, g, lb or oz — get rest energy in joules, kWh and TNT equivalents with step-by-step working.
Earth Curvature Calculator
Calculate how much Earth's surface curves over a distance, the hidden height below the horizon, and your horizon distance from any observer height.
Earth Orbit Calculator
Calculate orbital velocity, period, revolutions per day, and escape velocity for any circular orbit around Earth by altitude.
Eco-Friendly Bags Calculator
Estimate how many plastic bags you avoid and how much CO₂ you save by switching to reusable bags, accounting for bag manufacturing.
Effective Nuclear Charge Calculator
Calculate the effective nuclear charge Z_eff felt by an electron in any atomic orbital using Slater's rules — enter the atomic number and choose the orbital.
Efficiency Calculator
Calculate efficiency as useful output divided by total input, and compare against the Carnot efficiency limit for heat engines operating between two temperatures.
EIRP Calculator
Calculate EIRP (dBm, dBW, and watts) from transmitter power, antenna gain, and cable loss, plus optional power density at a given range.
弹性碰撞计算器
计算一维弹性碰撞后、动量和能量守恒条件下的末速度。
Elastic Constants Calculator
Convert between Young's modulus, shear modulus, bulk modulus and Poisson's ratio for isotropic linear-elastic materials.
点电荷电场计算器
计算点电荷在给定距离处的电场强度,并观察电场随距离的衰减。
Electric Motor Torque Calculator
Calculate shaft torque, angular velocity and full-load current for an electric motor from rated power, speed and efficiency.
点电荷电势计算器
计算点电荷在某距离处产生的电势(电压)及测试电荷在该处的能量。
Electrical Mobility Calculator
Calculate carrier mobility μ from drift velocity and electric field, then derive conductivity and resistivity from carrier density.
Electrical Power Calculator
Solve for electrical power, voltage, current or resistance — enter any two of the four quantities and get the rest instantly.
Electrolysis Calculator
Calculate the mass deposited or dissolved during electrolysis using Faraday's first and second laws: m = (M × I × t) / (n × F).
Electromotive Force (EMF) Calculator
Calculate the EMF of a battery or cell from terminal voltage, current and internal resistance using ε = V_t + I·r.
Electron Configuration Calculator
Find the electron configuration of any element (Z = 1–118) using the Aufbau principle — orbital notation plus shell-by-shell electron count.
Electron Speed (Drift Velocity) Calculator
Calculate the drift velocity of electrons in a conductor from current, wire diameter and material using v = I / (n·A·e).
Electronegativity Calculator
Calculate the electronegativity difference (ΔEN) between two atoms to predict bond type: nonpolar covalent, polar covalent or ionic.
Elongation Calculator
Calculate percentage elongation, engineering strain, true strain and reduction of area from tensile test gauge-length measurements.
实验式计算器
从各元素的质量百分数或质量确定化合物的实验式。
Energy Density of Electric and Magnetic Fields Calculator
Calculate the energy density stored in electric and magnetic fields using uₑ = ε₀E²/2 and u_B = B²/(2μ₀).
Energy to Wavelength Calculator
Convert photon energy (eV, meV, keV or J) to wavelength (nm, m) and frequency using the Planck relation λ = hc/E.
Engine Displacement Calculator
Calculate engine displacement in cc, litres and cubic inches from bore, stroke and cylinder count using V = (π/4) × bore² × stroke × cylinders.
Enthalpy Change Calculator (ΔH = mcΔT)
Calculate enthalpy change for heating or cooling any substance using ΔH = m × cₚ × ΔT, with built-in specific heat values for common materials.
反应焓计算器(赫斯定律)
利用赫斯定律和标准生成热计算标准反应焓 ΔH。
Entropy Change Calculator (ΔS)
Calculate entropy change ΔS for isothermal heat transfer, heating or cooling a substance, or ideal gas expansion — three standard thermodynamic formulas.
熵变计算器(ΔS)
从产物和反应物的标准摩尔熵计算标准反应熵 ΔS。
Enzyme Activity Calculator
Calculate enzyme activity in U/mL and specific activity in U/mg from a spectrophotometric assay using the Beer-Lambert law.
平衡常数(Kc)计算器
从平衡浓度和化学计量系数计算平衡常数 Kc。
逃逸速度计算器
使用 v=√(2GM/R) 计算逃离行星或恒星所需的最低速度,附预设值。
Evaporation Rate Calculator
Estimate the vapor-pressure driven evaporation rate (mm/day) from water surface temperature, air temperature, humidity and wind speed.
Excess Electrons Calculator
Find the number of excess electrons from a net charge using Q = n × e, where e = 1.602176634 × 10⁻¹⁹ C.
Exhaust Pipe Diameter Calculator
Calculate the minimum exhaust pipe internal diameter for a 4-stroke engine from displacement, RPM, volumetric efficiency and exhaust temperature.
Exoplanet Calculator
Calculate exoplanet orbital period, equilibrium temperature, transit depth and transit probability from stellar and orbital parameters.
Exoplanet Travel Planner
Calculate relativistic travel time to any exoplanet: Earth-frame and ship-frame duration, Lorentz factor, length contraction, and time dilation.
Factor of Safety Calculator
Calculate the factor of safety (FOS) by dividing the failure load by the applied load, with engineering category guidance.
Fan Calculator
Apply the fan affinity laws to predict new flow rate, pressure, and shaft power when fan speed changes — ideal for VFD-controlled HVAC fans.
法拉第电解计算器
利用法拉第定律,计算电解过程中沉积物质的质量和摩尔数。
法拉第定律感应电动势计算器
根据线圈匝数和磁通量变化率,计算线圈中的感应电动势。
Faraday's Law of Electrolysis Calculator
Calculate the mass deposited or dissolved in electrolysis using Faraday's laws: m = (M × I × t) / (z × F).
FCR Calculator
Calculate Feed Conversion Ratio (FCR) for livestock, aquaculture, and poultry — how many kg of feed produce 1 kg of live weight gain.
Fermi Level Calculator
Calculate the Fermi energy level position in intrinsic, n-type, and p-type semiconductors from temperature, bandgap, and doping concentration.
一级反应半衰期计算器
从速率常数求一级反应的半衰期和剩余浓度。
Fish Mercury Calculator
Estimate your weekly methylmercury intake from fish consumption and compare it with the EPA reference dose for your body weight.
Flat vs Round Earth Calculator
Calculate horizon distance and curvature drop on a spherical Earth; compare to the flat-Earth prediction of zero drop at any distance.
Flight Emissions Calculator
Estimate the CO₂ equivalent emissions of a flight per passenger, by distance and cabin class, compared to car and train alternatives.
Flow Rate Calculator
Calculate volumetric flow rate through a circular pipe from inner diameter and mean velocity in GPM, L/min, m³/s, and cfs, plus Reynolds number.
Flyback Converter Calculator
Design a flyback DC-DC converter: CCM duty cycle, peak primary/secondary currents, critical inductance, and MOSFET voltage stress.
Flywheel Energy Storage Calculator
Calculate the kinetic energy stored in a spinning flywheel from its mass, radius, RPM and geometry using E = ½Iω².
Foot-Pounds of Energy Calculator
Calculate work or energy in foot-pounds (ft·lbf) from force (lbf) and distance (ft), then convert to joules, BTU, calories and kWh.
力计算器 (F=ma)
使用牛顿第二定律 F = m × a 根据质量和加速度计算力。即时以牛顿、千牛顿和千克力给出结果。
Forward Converter Calculator
Calculate the output voltage of a single-transistor forward converter from its input voltage, duty cycle, and transformer turns ratio.
自由落体计算器
根据下落高度计算自由落体时间、撞击速度和距离。
Free-Space Path Loss Calculator
Calculate free-space path loss (FSPL) in dB from distance and frequency using the Friis transmission equation for wireless link budgets.
Freezing Point Depression Calculator
Calculate the freezing point depression of a solution using ΔTf = Kf × m × i for water, benzene, cyclohexane and more.
Frequency Bandwidth Calculator
Calculate bandwidth, centre frequency, Q factor and fractional bandwidth from two cutoff frequencies for any filter or RF system.
Frequency of Light Calculator
Convert wavelength (nm) to frequency (THz), period (fs), photon energy (eV) and wavenumber (cm⁻¹) using c = f × λ and E = hf.
Frequency to Wavelength Calculator
Convert any EM wave frequency (Hz to THz) to wavelength in metres, cm and nm using λ = c / f, the speed of light.
Fresnel Zone Calculator
Calculate the nth Fresnel zone radius for a radio link to determine the required line-of-sight clearance for Wi-Fi, microwave and wireless links.
Friction Coefficient Calculator
Calculate the coefficient of friction (μ) from measured forces, mass and applied force, or the incline angle at which an object just slides.
Friction Force Calculator
Calculate friction force, normal force and net acceleration on a flat or inclined surface using F = μN. Includes common surface presets.
摩擦力计算器
根据摩擦系数和法向力计算静摩擦力或动摩擦力,f=μN。
Friction Loss Calculator
Calculate pipe friction head loss and pressure drop using the Darcy–Weisbach equation from friction factor, pipe length, diameter and flow velocity.
Froude Number Calculator
Calculate the Froude number for open-channel flow and classify the regime as subcritical, critical or supercritical from velocity and flow depth.
Fulcrum Calculator
Calculate effort force, load, or arm lengths for a lever. Uses the principle of moments: Effort × Effort Arm = Load × Load Arm.
G-Force Calculator
Convert acceleration (m/s²) to g-force, or calculate the g-force in a turn from speed and radius, with human tolerance reference bands.
Gas Density Calculator
Calculate the density of any gas at a given temperature and pressure using the ideal gas law ρ = PM/RT.
Gauss's Law Calculator
Calculate electric flux and the electric field at a Gaussian surface radius using Gauss's law Φ = Q/ε₀.
Gay-Lussac's Law Calculator
Solve Gay-Lussac's law P₁/T₁ = P₂/T₂ for any unknown pressure or temperature of a gas at constant volume.
GDU Calculator
Calculate Growing Degree Units (GDU/GDD) from daily temperatures and a base temperature. Predict crop development stages.
Gear Ratio Calculator
Calculate the gear ratio from driver and driven gear tooth counts, with output speed and torque multiplication.
Gear Ratio RPM Calculator
Find output shaft RPM from input RPM and gear ratio. A curve plots output speed across the full ratio range.
Gear Ratio Speed Calculator
Calculate vehicle speed (km/h, mph) from engine RPM, transmission gear ratio, final drive ratio, and tyre diameter.
Gear Transmission Calculator
Calculate gear ratio, output speed, output torque and mechanical power for any gear, chain or belt-drive transmission.
Generator Power Calculator
Calculate real power (kW), apparent power (kVA) and reactive power (VAR) for single-phase, three-phase or DC generators from voltage, current and power factor.
吉布斯自由能计算器(ΔG = ΔH − TΔS)
从焓变、熵变和温度计算吉布斯自由能变 ΔG,并判断反应的自发性。
Global Plastic Policy Calculator
Estimate global plastic waste leakage and model policy impacts — production cuts and recycling increases — using editable 2022 baseline figures.
Goat Gestation Calculator
Calculate the expected kidding (birth) date for a goat from the breeding date. Goats average 150 days gestation (range 145–155 days).
Gold Weight Calculator
Calculate the pure gold content and market value of a gold piece from its weight, karatage, and current spot price.
Graham's Law of Diffusion Calculator
Calculate the diffusion and effusion rate ratio of two gases using Graham's Law: Rate₁/Rate₂ = √(M₂/M₁).
Grain Bin Calculator
Calculate grain bin storage capacity in bushels and tonnes from diameter, eave height, and grain type (corn, wheat, soybeans and more).
Grain Conversion Calculator
Convert grain quantities between US bushels, pounds, kilograms, metric tonnes, short tons, and hundredweight for corn, wheat, soybeans, and more.
Grams per cc Calculator
Calculate density in g/cc (g/cm³) from mass and volume, or find mass or volume when density is known.
克转摩尔计算器
使用物质摩尔质量将以克为单位的质量转换为摩尔数。
Gravitational Force Calculator
Calculate the gravitational attraction between two masses using F = G·m₁·m₂/r². Defaults show the Earth–Moon system.
Ground Speed Calculator
Calculate aircraft ground speed from true airspeed and wind using the wind triangle. Shows headwind, crosswind and wind correction angle.
Guinea Pig Age Calculator
Convert your guinea pig's age to the human equivalent. Shows the life stage from baby to geriatric and age relative to typical lifespan.
Guinea Pig Pregnancy Calculator
Track a guinea pig pregnancy: enter days since mating to see days remaining, progress percentage and whether the due date has passed.
宜居带计算器
根据恒星光度计算其宜居带(金发姑娘区)的内外边界距离。
Hair Diffraction Calculator
Calculate the diameter of a human hair from single-slit laser diffraction: enter the wavelength, screen distance and dark fringe position.
Hall Coefficient Calculator
Calculate the Hall coefficient R_H from Hall voltage, sample thickness, current and magnetic field, plus carrier density and type.
Hamster Age Calculator
Convert your hamster's age in months to a human age equivalent, with life stage and remaining lifespan for five common species.
Hand Dryers vs Paper Towels Calculator
Compare annual CO₂ emissions and costs of electric hand dryers versus paper towels using lifecycle data and your local electricity grid intensity.
Harmonic Wave Equation Calculator
Calculate wave speed, period, angular frequency and wave number from amplitude, frequency, wavelength and phase using y = A sin(kx − ωt + φ).
Heat Capacity Calculator
Calculate heat energy absorbed or released by a substance using Q = mcΔT. Includes specific heat values for 14 common materials.
热机效率计算器
根据热输入和功输出,或热输入和热排出,求实际热机的热效率。
Heat Exchanger Effectiveness–NTU Calculator
Calculate heat exchanger effectiveness from NTU and capacity ratio using the ε–NTU method for counter-flow or parallel-flow arrangements.
Heat Index Calculator
Calculate the apparent temperature ("feels like") from air temperature and humidity using the NOAA Rothfusz heat index equation.
Heat of Combustion Calculator
Calculate the heat released by burning a fuel using its lower heating value (LHV). Covers common fuels — natural gas, petrol, diesel, hydrogen, coal and more.
Heat Transfer Calculator
Calculate the heat absorbed or released by a substance using Q = mcΔT. Choose from common materials or enter a custom specific heat capacity.
Heat Transfer Coefficient Calculator
Calculate the overall heat transfer coefficient (U-value) and thermal resistances for a flat wall with convection on both sides using 1/U = 1/h_i + d/k + 1/h_o.
Heisenberg Uncertainty Principle Calculator
Calculate the minimum uncertainty in momentum (Δp) or time (Δt) from a known position (Δx) or energy (ΔE) spread using Heisenberg's principle: Δx·Δp ≥ ℏ/2.
Helical Coil Calculator
Calculate the wire length and inductance of a single-layer helical coil from its number of turns, mean diameter and coil length.
Helmholtz Resonator Calculator
Calculate the resonant frequency of a Helmholtz resonator (bottle, cavity, bass reflex port) from its volume, neck length and radius.
亨德森-哈塞尔巴尔赫缓冲液计算器
使用亨德森-哈塞尔巴尔赫方程,根据 pKa 和共轭碱与酸的比值求缓冲液 pH。
High-Pass Filter Calculator
Calculate the cutoff frequency and time constant of an RC high-pass filter from resistance and capacitance.
Hohmann Transfer Calculator
Calculate the two delta-v burns and transfer time for a Hohmann orbital transfer between two co-planar circular orbits around Earth, Moon, Mars, or the Sun.
胡克定律计算器
使用 F=kx 根据弹簧常数和形变量计算弹簧力;可求解任意变量。
Hoop Stress Calculator
Calculate hoop (circumferential) and longitudinal stress in a thin-walled cylindrical pressure vessel using σ = Pr/t.
Horse Gestation Calculator
Calculate the expected foaling date and gestation progress for a mare from the breeding date. Average equine gestation is 340 days.
Horse Weight Calculator
Estimate a horse's weight using Caslick's formula: (Heart Girth² × Body Length) / 330. No scale needed — just a measuring tape.
How Big Will My Cat Get Calculator
Estimate your kitten's adult size from its current age and weight using a veterinary growth curve. Includes breed-size and sex adjustments.
HP to Amps Calculator
Convert horsepower to amperes for DC, single-phase or three-phase AC motors using NEC standard formulas — enter HP, voltage, efficiency and power factor.
哈勃定律距离计算器
利用哈勃定律根据星系的退行速度估算其距离。
Hydraulic Conductivity Calculator
Calculate soil hydraulic conductivity K from constant-head or falling-head permeameter test data using Darcy's law.
Hydraulic Gradient Calculator
Calculate the hydraulic gradient i = Δh/L and Darcy seepage velocity/flow rate for groundwater or pipe flow.
Hydraulic Jump Calculator
Calculate the sequent depth, Froude numbers, energy loss and power dissipated in a hydraulic jump in an open rectangular channel.
Hydraulic Pressure Calculator
Calculate hydrostatic pressure at a given depth in any fluid using P = ρgh, with results in Pa, kPa, bar, psi and atm.
Hydraulic Radius Calculator
Calculate the hydraulic radius R_h = A/P for rectangular, circular and trapezoidal channels, then apply Manning's equation for velocity and flow rate.
Hydraulic Retention Time (HRT) Calculator
Calculate HRT = V/Q for wastewater treatment reactors, ponds or tanks in days, hours, minutes and seconds.
Hydroelectric Power Calculator
Calculate hydroelectric power output P = η·ρ·g·Q·H and annual energy generation from head, flow rate and turbine efficiency.
Hydrogen Ion Concentration Calculator
Convert pH to [H⁺] concentration or vice versa — get pOH, [OH⁻], and acid/base classification instantly.
Hydrogen-Like Atom Calculator
Calculate Bohr energy levels, orbital radii, and emission wavelengths for hydrogen-like ions using the Rydberg formula.
Hydrostatic Pressure Calculator
Calculate gauge and absolute pressure at any depth in water, seawater, mercury or a custom fluid using P = ρgh.
Ideal Gas Density Calculator
Calculate the density of any ideal gas from pressure, temperature and molar mass using ρ = PM/(RT). Outputs kg/m³, g/L and molar volume.
理想气体定律(PV = nRT)计算器
求解理想气体定律 PV = nRT 中的压强、体积、摩尔数或温度。
Ideal Gas Pressure Calculator
Calculate the pressure of an ideal gas from moles, temperature and volume using PV = nRT. Outputs in Pa, atm, kPa, bar and psi.
Ideal Gas Temperature Calculator
Find the temperature of an ideal gas from pressure, volume, and moles. Outputs Kelvin, Celsius, and Fahrenheit.
Ideal Gas Volume Calculator
Calculate the volume of an ideal gas from pressure, temperature, and moles using PV = nRT. Outputs litres and cubic metres.
Ideal Rocket Equation Calculator
Calculate rocket delta-v using Δv = Isp × g₀ × ln(m₀/mf). Enter wet mass, dry mass, and specific impulse.
Ideal Transformer Calculator
Calculate secondary voltage, current, and turns ratio for an ideal transformer. Enter V₁, N₁, N₂, and optionally I₁.
Immersed Weight Calculator
Calculate the apparent weight of any fully-submerged object using Archimedes' principle and compare buoyancy to actual weight.
Impact Energy Calculator
Calculate the kinetic energy at impact from mass and velocity, or from free-fall drop height. Optionally compute average impact force from stopping distance.
Impact Test Calculator
Calculate the energy absorbed by a material specimen in a Charpy or Izod pendulum impact test and compute impact toughness (J/mm²).
Impulse and Momentum Calculator
Calculate impulse, change in momentum, average force or contact time using the impulse-momentum theorem J = F·Δt = m·Δv.
冲量计算器
根据力和时间或动量变化求冲量,J=FΔt=mΔv。
斜面计算器
斜面上质量块在可选摩擦条件下的受力和加速度。
Index of Refraction Calculator
Calculate the index of refraction from the speed of light in a medium (n = c/v) or using Snell's law from angles of incidence and refraction.
Inductive Reactance Calculator
Calculate inductive reactance of an inductor in AC circuits. Enter frequency (Hz) and inductance (H) to get X_L in ohms.
Inductor Energy Calculator
Calculate the energy stored in an inductor's magnetic field. Enter inductance (H) and current (A) to get energy in joules.
Insertion Loss Calculator
Calculate insertion loss in dB from power or voltage ratios. Enter input and output values to get insertion loss and the power/voltage ratio.
Internal Resistance Calculator
Calculate the internal resistance of a battery or power source from its EMF, terminal voltage and load current.
Intrinsic Carrier Concentration Calculator
Calculate the intrinsic carrier concentration nᵢ of silicon, germanium or GaAs at any temperature using the effective density-of-states model.
Inverse Square Law Calculator
Calculate how intensity changes with distance using the inverse square law: I₂ = I₁ × (r₁/r₂)². Covers light, sound, gravity and radiation.
Inverting Buck-Boost Converter Calculator
Calculate output voltage, inductor currents and ripple for an inverting buck-boost DC-DC converter from duty cycle and component values.
Ionic Strength Calculator
Calculate ionic strength I = ½ Σ cᵢzᵢ² for any electrolyte solution and estimate the mean activity coefficient via the Davies equation.
Isentropic Flow Calculator
Compute isentropic flow ratios T/T₀, P/P₀, ρ/ρ₀ and A/A* for any Mach number and ratio of specific heats (γ).
Isoelectric Point Calculator (pI)
Calculate the isoelectric point (pI) of an amino acid from its pKa values and plot net charge versus pH.
J-Pole Antenna Calculator
Calculate J-pole antenna dimensions — radiating element, matching stub, gap and feed point — for any frequency and velocity factor.
Joule Heating Calculator
Calculate the heat energy dissipated by an electric current through a resistor using Joule's law: Q = I² × R × t.
Ka 转 pKa 计算器
将酸解离常数 Ka 转换为 pKa(及反向),以及共轭碱的 Kb 和 pKb 值。
Kaya Identity Calculator
Decompose CO₂ emissions into population, GDP per capita, energy intensity and carbon intensity using the Kaya Identity. Model any country or scenario.
开普勒第三定律计算器(轨道周期)
根据半长轴和中心天体质量,利用开普勒第三定律求轨道周期。
kg to Newtons Calculator
Convert kilograms (mass) to Newtons (weight force) using F = m × g. Includes Earth, Moon, Mars and custom gravity values.
Kinematic Viscosity of Air Calculator
Calculate the kinematic viscosity of air at any temperature and pressure using Sutherland's law and the ideal-gas equation.
运动学计算器(SUVAT)
在恒定加速度运动中求解速度、时间、位移或加速度。
动能计算器
使用 KE = ½mv² 根据运动物体的质量和速度计算其动能。结果以焦耳、千焦和千卡给出。
Knudsen Number Calculator
Calculate the Knudsen number (Kn = λ/L) from temperature, pressure, molecular diameter and length scale to identify the gas flow regime.
Kp 与 Kc 转换器
使用 Kp = Kc(RT)^Δn 在气相平衡常数 Kp 与 Kc 之间进行转换。
Kp Calculator
Convert Kc to Kp using Kp = Kc × (RT)^Δn and calculate ΔG° from the equilibrium constant at a given temperature.
Ksp 溶解度计算器
计算任意 AxBy 化学计量盐的 Ksp 与摩尔溶解度之间的转换。
kVA Calculator
Calculate apparent power (kVA), real power (kW), reactive power (kVAR) and power factor for AC electrical systems.
kVA to Amperage Calculator
Convert kVA (apparent power) to amps for single-phase and three-phase systems. Shows active power at common power factors.
Langmuir Isotherm Calculator
Calculate equilibrium adsorption capacity using the Langmuir isotherm model: q = qmax·KL·C / (1 + KL·C).
Laser Beam Divergence Calculator
Calculate laser beam divergence, Rayleigh range, and beam radius at any distance using Gaussian beam propagation.
Laser Beam Expander Calculator
Calculate the output beam diameter and divergence of a laser beam expander from magnification M: D_out = M·D_in, θ_out = θ_in/M.
Laser Brightness (Radiance) Calculator
Calculate laser brightness (radiance) B = P/(A·Ω) in W/(cm²·sr) from power, beam radius, far-field divergence and M² beam quality.
Laser Linewidth Calculator
Convert laser frequency linewidth Δν (MHz) to wavelength linewidth Δλ (nm) and compute coherence length and coherence time at any center wavelength.
Laser Spot Size Calculator
Calculate the focused spot size, Rayleigh range and depth of focus for a Gaussian laser beam through a thin lens using M²·λ·f/(π·w).
相变潜热计算器
使用 Q = mL 计算熔化或沸腾所需的热量,可选融化潜热或汽化潜热。
Lattice Energy Calculator
Calculate ionic crystal lattice energy using the Born-Landé equation from the Madelung constant, ion charges, interionic distance and Born exponent.
LC Filter Calculator
Calculate the resonant frequency, characteristic impedance and reactance of an LC filter or tank circuit. Supports H, mH, μH, nH and F, μF, nF, pF.
LC Resonant Frequency Calculator
Calculate the resonant frequency, period, and characteristic impedance of an LC tank circuit from inductance and capacitance.
LED Resistor Calculator
Calculate the series resistor value needed for an LED circuit from supply voltage, LED forward voltage and desired current — with E24 nearest standard value.
Lensmaker's Equation Calculator
Compute a thin lens's focal length and optical power from its refractive index and radii of curvature using the lensmaker's equation.
Lever Calculator
Calculate effort force, load force, arm lengths and mechanical advantage for any lever. Enter three values and solve for the fourth.
Lift Coefficient Calculator
Calculate the lift coefficient (CL) or lift force from air density, airspeed and wing area using the fundamental aerodynamic lift equation.
光年、秒差距与天文单位转换器
在光年、秒差距、天文单位、千米和米之间转换天文距离。
Lightning Distance Calculator
Calculate how far away a lightning strike was by timing the delay between the flash and the thunder, with temperature-corrected speed of sound.
限量试剂计算器
从反应物质量和方程式系数确定限量反应物及过量量。
Linear Actuator Force Calculator
Calculate the push (extension) and pull (retraction) force of a hydraulic or pneumatic cylinder from pressure and bore/rod diameters.
Liquid Ethylene Density Calculator
Calculate the density of liquid ethylene (C₂H₄) at any temperature from −103.77 °C to 9.20 °C using the Rackett equation.
Livestock Fence Calculator
Calculate fence perimeter, number of posts and total wire or rail needed for a rectangular or circular livestock enclosure.
Llama Calculator
Calculate pack weight capacity and daily dry-matter feed requirements for llamas based on body weight, trip length, and herd size.
LMTD Calculator
Calculate the Log Mean Temperature Difference (LMTD) for counterflow and parallel-flow heat exchangers from hot and cold inlet/outlet temperatures.
Log Reduction Calculator
Calculate the log reduction in microbial count after disinfection or sterilisation, plus the percentage reduction and surviving fraction.
洛伦兹力计算器
根据电场和磁场矢量及速度矢量,计算电荷所受的完整洛伦兹力。
Lotka–Volterra Equations Calculator
Compute the equilibrium populations, cycle period, and phase portrait for the Lotka–Volterra predator–prey model from its four rate parameters.
Low-Pass Filter Calculator
Calculate the −3 dB cutoff frequency, time constant and Bode plot of a first-order RC low-pass filter from R and C values.
Lumen Calculator
Convert lumens to lux (illuminance), calculate luminous efficacy (lm/W), and find how many lumens a room needs for a target brightness.
Luminosity Calculator
Calculate the luminosity of any star from its radius and surface temperature using the Stefan-Boltzmann law (L = 4πR²σT⁴).
Lux to Foot-candle Calculator
Instantly convert between lux (lm/m²) and foot-candles (lm/ft²) — exact SI and imperial illuminance unit conversion with a reference scale.
Mach Number Calculator
Calculate Mach number from object speed and air temperature, with subsonic, transonic, supersonic and hypersonic classification.
Magnetic Declination Calculator
Convert a compass (magnetic) bearing to a true geographic bearing using your local magnetic declination, or reverse the correction.
Magnetic Dipole Moment Calculator
Calculate the magnetic dipole moment of a current loop and the resulting far-field B on axis and at the equator.
Magnetic Field of a Straight Wire Calculator
Find the magnetic field at a perpendicular distance from a long straight current-carrying wire using Ampere's law.
磁通量计算器
根据磁场强度、面积和与法线的夹角计算穿过表面的磁通量。
Magnetic Force Between Parallel Wires Calculator
Calculate the magnetic force per unit length between two parallel current-carrying wires — attractive for same-direction currents, repulsive for opposite.
载流导线所受磁力计算器
根据电流、长度、磁场和角度,求磁场中载流导线所受磁力。
运动电荷所受磁力计算器
使用 F = qvB sin(theta) 计算穿过磁场运动的带电粒子所受磁力。
Magnetic Moment Calculator
Calculate the magnetic moment of a multi-turn coil and the resulting torque and potential energy when placed in a magnetic field.
Magnetic Permeability Calculator
Calculate absolute permeability, magnetic flux density B, and susceptibility from relative permeability μr and field intensity H.
Magnitude of Acceleration Calculator
Calculate the magnitude and direction of an acceleration vector from its x, y (and optional z) components.
Magnus Force Calculator
Calculate the Magnus force on a spinning ball or cylinder: the sideways lift that curves a football, baseball or cricket ball in flight.
Malus's Law Calculator
Calculate transmitted light intensity through a polariser using Malus's law: I = I₀ cos²(θ).
Manometer Calculator
Calculate gauge and absolute pressure from a fluid column in a manometer using P = ρgh, with conversion to Pa, kPa, bar, psi, mmHg or atm.
质量分数计算器
根据溶质质量和溶液总质量计算溶质的质量分数。
Mass to Density Calculator
Calculate density from mass and volume, or solve for mass or volume when density is known. Supports g, kg, lb, cm³, L, m³.
质能等价(E = mc²)计算器
用爱因斯坦的 E = mc² 将质量转换为能量。输入质量即可得到以焦耳、千瓦时和百万吨当量表示的等效能量。
Mean Free Path Calculator
Calculate the mean free path of gas molecules (λ = k_B T / (√2 π d² P)) for common gases at any temperature and pressure.
Meat Footprint Calculator
Estimate your annual CO₂e emissions from weekly meat consumption (beef, pork, chicken, lamb, fish) using 2018 global median emission factors.
Mechanical Advantage Calculator
Calculate the ideal mechanical advantage of a lever, inclined plane, wheel-and-axle, or pulley from its dimensions.
Michaelis-Menten Equation Calculator
Calculate the reaction rate v from Vmax, Km and substrate concentration [S] using the Michaelis-Menten equation of enzyme kinetics.
Miller Indices Calculator
Calculate interplanar spacing d and Bragg diffraction angle 2θ for any (hkl) plane in a cubic crystal lattice.
Mirror Equation Calculator
Solve the mirror equation 1/f = 1/dₒ + 1/dᵢ for concave or convex mirrors — enter any two values to find the third.
Mixed Air Calculator
Calculate mixed air dry-bulb temperature, humidity ratio and enthalpy for HVAC systems mixing outdoor and return air streams.
Mixed Air Temperature Calculator
Calculate the resulting temperature when two air streams of different flow rates and temperatures are mixed — for HVAC and ventilation.
Mixing Ratio Calculator
Calculate the mixing ratio of two substances: get the simplified ratio, percentage share of each component and parts per unit.
Mixing Ratio of Air Calculator
Calculate the atmospheric mixing ratio (g/kg), relative humidity, specific humidity and vapour pressure from temperature, dew point and pressure.
MLVSS Calculator
Calculate MLVSS from MLSS and volatile fraction, plus F/M ratio, hydraulic retention time and organic loading rate for activated-sludge systems.
MOA Calculator
Calculate 1 MOA size at any shooting distance and find the scope clicks needed to correct point-of-impact error.
Modulation Calculator
Calculate AM or FM modulation index, Carson bandwidth, sideband frequencies, and AM power efficiency from carrier and message parameters.
Mohr's Circle Calculator
Find principal stresses, maximum shear stress and principal-plane angle from a 2D stress state (σx, σy, τxy) with Mohr's circle.
Moisture Content Calculator
Calculate the moisture content of any material on a wet basis and dry basis from wet and oven-dried masses.
质量摩尔浓度计算器
根据溶质的摩尔数和以千克计的溶剂质量计算质量摩尔浓度(mol/kg)。
摩尔质量计算器
根据化学式(如 H2O、C6H12O6 或 Ca(OH)2)求任意化合物的摩尔质量(g/mol)。
Molar Ratio Calculator
Calculate the molar ratio of two substances from their masses and molar masses — essential for stoichiometry and limiting-reagent problems.
摩尔浓度计算器
根据溶质的摩尔数或克数以及溶液体积计算摩尔浓度(mol/L)。
Mole Calculator
Convert between grams, moles, and number of molecules using molar mass and Avogadro's number.
摩尔分数计算器
通过各组分的摩尔数或质量,计算混合物中每种组分的摩尔分数。
分子式计算器
根据实验式和化合物的摩尔质量,求分子式。
Molecular Weight Calculator
Calculate the molar mass of any compound by typing its chemical formula — supports parentheses and 60+ elements.
摩尔转原子/分子数计算器
利用阿伏伽德罗常数,实现摩尔数与粒子数(原子、分子、离子)的相互换算。
Moles to Atoms Calculator
Convert moles to atoms or molecules using Avogadro's constant, and optionally convert to grams with molar mass.
摩尔换算克数计算器
利用摩尔质量将物质的摩尔数转换为克数。快速摩尔到克的换算。
转动惯量计算器
根据质量和尺寸计算常见形状(球、圆盘、杆)的转动惯量。
动量计算器
计算线动量 p=mv,或由动量求质量或速度。
MOSFET Calculator
Calculate NMOS MOSFET drain current I_D in cutoff, triode and saturation regions given V_GS, V_th, V_DS and transconductance parameter k_n.
MOSFET Threshold Voltage Calculator
Calculate MOSFET threshold voltage V_th from substrate doping N_A, oxide thickness t_ox and flat-band voltage V_fb using long-channel device physics.
Mowing Cost Calculator
Estimate lawn mowing cost per session and annually from area, mowing speed, labour rate, fuel cost and number of sessions per year.
Muzzle Velocity & Energy Calculator
Calculate muzzle energy in ft-lb and joules, SI momentum, IPSC power factor, and a projectile trajectory arc from bullet mass and velocity.
Natural Frequency Calculator
Calculate the natural frequency, angular frequency, and period of a spring-mass system, simple pendulum, or LC resonant circuit.
NE555 Astable Calculator
Calculate the output frequency, period, high/low times and duty cycle of an NE555 timer wired in astable (free-running oscillator) mode.
能斯特方程计算器
由标准电极电位 E°、转移电子数和反应商 Q 求非标准电池电位 E。
Net Ionic Equation Calculator
Derive net ionic equations from balanced molecular equations for common acid–base, precipitation, and gas-forming reactions in step-by-step detail.
Neutralization Calculator
Calculate the volume of base needed to neutralize an acid (or vice-versa) using acid–base stoichiometry and molar equivalents.
Newton's Law of Cooling Calculator
Calculate the temperature of a cooling (or heating) object at any elapsed time using Newton's law of cooling: T(t) = T∞ + (T₀ − T∞) × e^(−kt).
Newton's Second Law Calculator
Solve Newton's second law F = m × a for force, mass, or acceleration. Enter any two values to calculate the third, plus weight and impulse.
Newton's Third Law Calculator
Apply Newton's third law: for every action force there is an equal and opposite reaction force. Enter the force and both masses to find accelerations.
Noise Figure Calculator
Compute cascaded noise figure, noise factor and noise temperature for a two-stage RF amplifier chain using the Friis formula.
Normal Force Calculator
Calculate the normal force on an inclined plane: N = mg cos θ. Optionally add friction force and net force along the slope.
Normality Calculator
Calculate the normality of a solution from mass, molar mass, n-factor and volume, and convert between normality and molarity.
NPSH Calculator
Calculate NPSH available for a pump system and check the cavitation margin against NPSH required.
Number Density Calculator
Calculate particle number density from N/V, mass density and molar mass, or ideal-gas pressure and temperature.
Nusselt Number Calculator
Calculate the Nusselt number by definition (Nu = hL/k), flat-plate correlation, or Dittus-Boelter pipe-flow formula.
Oblique Shock Calculator
Calculate shock wave angle, post-shock Mach number, pressure, temperature and density ratios for an oblique shock wave.
欧姆定律计算器
使用欧姆定律计算电压、电流、电阻和功率——输入任意两个值即可。
Olbers' Paradox Calculator
Calculate the fraction of night sky covered by stars and explore why an infinite universe still has a dark sky.
Olympic Games Sustainability Calculator
Estimate the carbon footprint of attending the Olympic Games covering flights, accommodation and local transport.
Omega-3 for Dogs Calculator
Calculate how much combined EPA+DHA your dog needs daily based on body weight and dosing level, and convert to fish oil capsules.
Open Channel Flow Calculator
Calculate discharge, velocity and Froude number for a rectangular open channel using Manning's equation (SI units).
Optical Density Calculator
Calculate absorbance, transmittance, concentration, or molar absorptivity using the Beer-Lambert law (A = εlc) for spectrophotometry.
光学放大率计算器
根据透镜或反射镜的像距和物距或高度计算放大率。
Orbital Period Calculator
Calculate the orbital period of any body using Kepler's Third Law: T = 2π √(a³ / GM). Works for planets, moons and satellites.
轨道速度计算器
由中心天体质量和轨道半径计算圆形轨道的速度和周期。
Orifice Flow Calculator
Calculate volumetric flow rate through a circular orifice using the Torricelli / orifice-flow equation Q = Cd·A·√(2gh).
Osmotic Pressure Calculator
Calculate osmotic pressure of a solution using the van't Hoff equation π = iMRT. Enter molarity, temperature and solute type.
Parallax Calculator
Calculate stellar distances in parsecs and light-years from an annual parallax angle, or find object distance from a terrestrial baseline and parallax angle.
Parallel Inductors Calculator
Calculate the equivalent inductance of 2–4 inductors connected in parallel. Uses the reciprocal-sum formula, assuming no mutual coupling.
平行板电容器计算器
根据极板面积、间距和介电常数,计算平行板电容器的电容。
Partial Pressure Calculator
Calculate the partial pressure of each gas in a mixture using Dalton's Law (P_i = x_i × P_total). Supports kPa, atm, bar, psi, mmHg.
Particle Velocity Calculator
Calculate the RMS speed, mean speed and most probable speed of gas particles using the kinetic theory of ideal gases — for any gas and temperature.
Passive House Calculator
Estimate a building's annual specific heating demand (kWh/m²·year) and check compliance with the Passive House standard of ≤ 15 kWh/m²·year.
Pendulum Frequency Calculator
Calculate the oscillation frequency of a simple pendulum from its length and local gravity. Includes period and angular frequency.
Pendulum Kinetic Energy Calculator
Calculate the maximum kinetic energy and speed of a pendulum bob at the bottom of its swing from mass, length, and release angle.
Pendulum Period Calculator
Calculate the period of a simple pendulum from length, gravity, and swing angle — includes large-angle correction beyond the small-angle formula.
元素质量百分比计算器
由化学式求化合物中每种元素的质量百分比。
Percent Ionic Character Calculator
Calculate the percent ionic character of a chemical bond from the electronegativity difference using the Pauling formula.
电离百分比计算器
由弱酸的 Ka 和初始浓度计算电离百分比、[H+] 和 pH。
Percent Solution Calculator
Calculate the concentration of a solution as a percentage — mass/volume %(w/v), mass/mass %(w/w), or volume/volume %(v/v).
产率计算器
由实际产量和理论产量计算反应产率。
Percentage Concentration to Molarity Calculator
Convert % w/w or % w/v concentration to molarity (mol/L) — enter percentage, molar mass, and density.
周期与频率转换器
在周期、频率和角频率之间转换。输入周期或频率,立即得到 T、f 和 ω。
Pet Sitter Rates Calculator
Estimate pet-sitting costs for dog walks, drop-in visits, overnight stays or day boarding — with multi-pet surcharges and a weekly total.
pH 计算器
求溶液的 pH、pOH、[H+] 和 [OH-]。立即在氢离子浓度和 pH 之间换算。
Phase Rule Calculator
Calculate the degrees of freedom (F) of a chemical system using the Gibbs Phase Rule F = C − P + 2, or the condensed form F = C − P + 1.
PHEV Economy Calculator
Calculate plug-in hybrid (PHEV) combined fuel economy (MPGe), annual fuel cost, and the electric vs gasoline mileage split based on your daily driving habits.
光电效应计算器
求光电效应中发射电子的最大动能、截止电压和阈值频率。
光子能量(E = hf)计算器
由频率或波长利用 E = hf = hc/λ 计算光子能量,结果以焦耳和电子伏特表示。
Physical Pendulum Calculator
Calculate the oscillation period, frequency and angular frequency of a physical (compound) pendulum using T = 2π√(I/mgd).
Pine Straw Calculator
Calculate how many bales of pine straw you need to cover a garden bed at a chosen depth, with area, volume and cost estimate.
Pipe Flow Calculator
Calculate pipe flow rate, Reynolds number, friction factor and pressure drop using the Darcy–Weisbach equation and Swamee–Jain approximation.
Pipe Flow Velocity Calculator
Calculate the average fluid velocity in a pipe from flow rate and internal diameter — with Reynolds number and flow regime.
Piston Force Calculator
Calculate the extend and retract force of a hydraulic or pneumatic cylinder from bore, rod diameter and operating pressure.
Piston Speed Calculator
Calculate mean and peak piston speed from stroke length and engine RPM — in m/s, ft/min and km/h.
pKa Calculator
Convert Ka to pKa, calculate buffer pH with Henderson-Hasselbalch, and find % ionization of a weak acid.
Plant Population Calculator
Calculate the total plant population, plants per hectare and plants per acre for any field from row and plant spacings.
Plants Calculator
Estimate a plant's daily water requirement and gross photosynthesis (O₂/CO₂) from pot size, leaf area, light and temperature.
Plastic Footprint Calculator
Estimate your annual single-use plastic waste in kg from weekly usage of bags, bottles, containers and packaging.
Pneumatic Cylinder Force Calculator
Calculate push and pull force of a pneumatic cylinder from bore diameter, rod diameter and operating pressure in bar.
pOH 计算器
计算氢氧根离子浓度对应的 pOH,并在 25°C 下实现 pOH、pH、[OH-] 和 [H+] 之间的相互转换。
Poise to Stokes Converter
Convert between dynamic viscosity (Poise, cP, Pa·s) and kinematic viscosity (Stokes, cSt, m²/s) using fluid density.
Poiseuille's Law Calculator
Calculate volumetric flow rate through a tube using the Hagen-Poiseuille equation: Q = πr⁴ΔP / (8ηL).
Poisson's Ratio Calculator
Calculate Poisson's ratio from axial and lateral strain, plus bulk and shear moduli when Young's modulus is known.
Polar Moment of Inertia Calculator
Calculate the polar moment of inertia (J) for solid and hollow circles and rectangles. Used in torsion, shaft, and beam design.
Porosity and Permeability Calculator
Calculate rock or soil porosity (φ = Vv/Vt) and intrinsic permeability in Darcy, millidarcy and m² using Darcy's law.
势能计算器
使用 PE = m·g·h 并取 g = 9.80665 m/s² 根据质量和高度计算重力势能。结果以焦耳和千焦给出。
Potting Soil Calculator
Calculate how many bags of potting soil you need for containers, raised beds or planters — rectangular or round pots, any bag size.
Pounds Per Minute Calculator
Convert mass flow rates between lb/min, lb/hr, lb/s, kg/min, kg/hr and g/s. See cumulative weight over 60 minutes at any rate.
Pounds Per Square Inch (PSI) Calculator
Calculate pressure in PSI from force (lbf) and area (in²), then convert to Pa, kPa, MPa, bar, atm and mmHg.
功率计算器
使用 P = W / t 将功率计算为功除以时间。即时以瓦特、千瓦和机械马力给出结果。
Power Dissipation Calculator
Calculate power dissipated in a resistive element. Enter any two of voltage, current or resistance to get watts plus daily energy consumption.
Power Factor Calculator
Calculate power factor, true power, reactive power and apparent power for AC circuits. Visualises the kW–kVAR–kVA power triangle.
Power-to-Weight Ratio Calculator
Calculate power-to-weight ratio in W/kg, kW/tonne and hp/ton from any power unit (kW, hp, PS) and mass unit (kg, lbs).
PPM 浓度计算器
在稀溶液中实现百万分之一(ppm)、ppb、mg/L 和质量分数之间的相互转换。
PPM to Molarity Calculator
Convert concentration from ppm (mg/kg) to molarity (mol/L, mM, μM, nM) using the solute molar mass and solution density.
Prandtl Number Calculator
Calculate the Prandtl number from dynamic viscosity, specific heat, and thermal conductivity — or from kinematic viscosity and thermal diffusivity.
Prandtl-Meyer Expansion Calculator
Calculate the downstream Mach number and isentropic property ratios for a Prandtl-Meyer expansion fan given upstream Mach number and turning angle.
压强计算器
使用 P = F / A 根据力和面积计算压强。即时以帕斯卡、千帕、psi 和巴给出结果。
Principal Stress Calculator
Calculate principal stresses σ₁ and σ₂, maximum shear stress, principal plane angle, and Von Mises stress from a 2D stress state.
抛体运动计算器
根据速度、角度和发射高度计算抛体的射程、最大高度和飞行时间。
Propeller Pitch Speed Calculator
Calculate theoretical boat top speed from propeller pitch, engine RPM and gear ratio. Find prop shaft RPM and speed in mph, knots and km/h.
Propeller Slip Calculator
Calculate propeller slip percentage from engine RPM, pitch, gear ratio and actual GPS speed. Find effective pitch and compare theoretical vs actual advance.
Protein Concentration Calculator
Calculate protein concentration in mg/mL, µg/mL and µM from dissolved mass and solution volume.
Protein Molecular Weight Calculator
Estimate protein molecular weight from residue count using the 110 Da average residue mass, with disulfide bond and Stokes radius output.
Protein Solubility Calculator
Estimate protein solubility relative to the optimal pH using the isoelectric point, buffer pH, and NaCl ionic strength via Cohn–Hofmeister principles.
Psychrometric Calculator
Calculate dew point, wet-bulb temperature, humidity ratio, enthalpy and specific volume from dry-bulb temperature and relative humidity.
Pulley Calculator
Calculate the mechanical advantage, required effort force, rope length to haul, and efficiency of a block-and-tackle pulley system.
Pump Horsepower Calculator
Calculate water horsepower, brake horsepower and motor power required for a pump given flow rate, total head, specific gravity and efficiencies.
Punnett Square Calculator
Calculate offspring genotype and phenotype probabilities for a monohybrid genetic cross using a 2×2 Punnett square.
Q10 Temperature Coefficient Calculator
Calculate the Q10 coefficient — how much a biological or chemical reaction rate changes per 10 °C temperature rise — from two rate–temperature pairs.
qPCR Efficiency Calculator
Calculate PCR amplification efficiency from the standard curve slope: E = 10^(−1/slope) − 1. Acceptable range is 90–110%.
Quantum Number Calculator
For a given shell n, find all allowed l and ml values, subshell names, electrons per subshell, shell capacity, and the hydrogen energy level.
Quarter Mile Calculator
Estimate quarter-mile elapsed time and trap speed from vehicle weight and horsepower using the Lawlor drag-racing formula.
Rabbit Cage Size Calculator
Calculate the minimum cage size your rabbit needs based on body length, shoulder height and breed — based on RWAF and House Rabbit Society guidelines.
Rabbit Coat Colour Genetics Calculator
Predict offspring coat colours from two parent rabbits using A-locus (agouti/self) and B-locus (black/chocolate) Mendelian genetics.
Rabbit Gestation Calculator
Calculate how far along a rabbit pregnancy is and how many days until the expected birth date, based on average 31-day rabbit gestation.
Radar Horizon Calculator
Calculate the maximum radar line-of-sight range using the 4/3-Earth-radius model: d = 4.12 × (√h₁ + √h₂) km from antenna and target heights.
Radiation Pressure Calculator
Calculate the pressure and force exerted by electromagnetic radiation on a surface — absorber or perfect reflector.
Radioactive Decay Calculator
Calculate how much of a radioactive isotope remains after a given time using the half-life decay formula N(t) = N₀ × e^(−λt).
放射性半衰期与衰变计算器
使用 N = N0·(1/2)^(t/T) 计算放射性衰变的剩余量、已过时间或半衰期。
Raised Bed Soil Calculator
Calculate how much soil mix you need to fill a raised garden bed by length, width and depth, with bag count estimates.
Raoult's Law Calculator
Calculate total vapour pressure, partial pressures, and vapour-phase composition of an ideal binary solution using Raoult's Law.
Rat Cage Size Calculator
Calculate the minimum cage floor area for pet rats based on welfare guidelines (2 sq ft per rat) and check whether your cage meets the recommended dimensions.
Rate Constant Calculator
Calculate the rate constant k using the Arrhenius equation from the pre-exponential factor A, activation energy Ea, and temperature.
速率定律计算器
根据速率定律 rate = k[A]^m[B]^n 计算反应速率,并求总反应级数。
Raw Dog Food Calculator
Calculate how much raw food to feed your dog per day. Uses BARF/Prey Model Raw guidelines: 2–3% of body weight for adults, more for puppies.
RC Circuit Calculator
Calculate the RC time constant τ = RC, charging/discharging voltage curves, and cutoff frequency for any resistor-capacitor circuit.
RC Filter Calculator
Calculate the cutoff frequency, time constant τ and gain response of a first-order RC low-pass or high-pass filter.
RC 时间常数计算器
求电阻-电容电路的 RC 时间常数,并绘制充电曲线。
Reaction Quotient Calculator
Calculate the reaction quotient Q for any equilibrium reaction aA + bB ⇌ cC + dD and compare it to Keq to find which direction the reaction proceeds.
Reaction Time & Stopping Distance Calculator
Calculate how far a vehicle travels during driver reaction time, the braking distance, and the total stopping distance at any speed.
Recoil Energy Calculator
Calculate free recoil energy, recoil velocity and momentum of a firearm using conservation of momentum. Inputs: bullet mass, muzzle velocity, gun mass.
Reconstitution Calculator
Calculate the concentration after adding diluent to a lyophilised drug powder, and find the volume to withdraw for a desired dose.
红移与视退行速度计算器
根据谱线计算星系的宇宙学红移 z 及视退行速度。
Redshift Calculator
Calculate cosmological redshift z from emitted and observed wavelengths, plus relativistic recession velocity and approximate Hubble distance.
Reduce Your Plastic Calculator
Calculate how much single-use plastic and CO₂ you can eliminate per year and over a lifetime by replacing bottles, bags, straws and containers with reusables.
Reduced Mass Calculator
Calculate the reduced mass μ = m₁m₂/(m₁+m₂) for two-body orbital mechanics, quantum mechanics and collision problems, in kg, g, amu or solar masses.
Refrigerant Capillary Tube Length Calculator
Estimate the required capillary tube length for a refrigerant circuit using Darcy-Weisbach for single-phase liquid flow.
Relative Humidity Calculator
Calculate relative humidity from air temperature and dew point using the Magnus formula, plus absolute humidity and comfort level.
Relativistic Kinetic Energy Calculator
Calculate relativistic kinetic energy KE = (γ−1)mc² at any fraction of the speed of light, with the Lorentz factor and a comparison to the classical ½mv².
相对论长度收缩计算器
使用洛伦兹收缩 L = L0/γ 计算高速运动物体的收缩长度。
相对论时间膨胀计算器
计算以光速分数运动的物体的相对论时间膨胀和洛伦兹因子。
Relativistic Velocity Addition Calculator
Add two relativistic velocities using Einstein's velocity addition formula and compare with the classical Galilean result.
Resistor Color Code Calculator
Decode 4-band or 5-band resistor color codes to find resistance in ohms and the tolerance range — instantly.
Resistor Noise Calculator
Calculate Johnson-Nyquist thermal noise voltage of a resistor: RMS noise, noise density, and noise power from resistance, temperature, and bandwidth.
Resistor Wattage Calculator
Calculate the power a resistor dissipates from V, I or R, find the minimum wattage rating, and apply the derating factor for reliable circuit design.
串并联电阻计算器
输入逗号分隔的电阻值,计算任意数量电阻串联和并联的总等效电阻。
Resultant Force Calculator
Find the magnitude and direction of the net force from two forces using vector addition — enter magnitudes and angles.
Resultant Velocity Calculator
Find the resultant speed and direction when two velocities combine — enter magnitudes and angles to get the net velocity vector.
Resuspension Calculator
Calculate how much buffer to add to a dried pellet or lyophilised sample to reach a target concentration for protein, DNA, RNA, or any compound.
Reverberation Time Calculator (RT60
Calculate room reverberation time (RT60) using Sabine's equation from room dimensions and average absorption coefficient.
Reynolds Number Calculator
Calculate the Reynolds number (Re = ρvL/μ) for pipe or external flow and determine whether the flow is laminar, transitional, or turbulent.
RLC Circuit Calculator
Analyse a series RLC circuit: natural frequency, damping ratio, quality factor, and whether the response is under-, over- or critically damped.
RLC Impedance Calculator
Compute the impedance of a series RLC circuit at any frequency: inductive reactance, capacitive reactance, total impedance and phase angle.
RLC 谐振频率计算器
求 RLC 电路的谐振频率,并查看感抗和容抗随频率变化的曲线。
RMS Speed Calculator
Calculate the root-mean-square speed, mean speed, and most-probable speed of gas molecules using the Maxwell–Boltzmann distribution.
RMS Voltage Calculator
Convert between peak voltage, peak-to-peak voltage and RMS voltage for a sine wave, plus form factor and crest factor.
Rocket Thrust Calculator
Calculate rocket engine thrust and specific impulse from mass flow rate and exhaust velocity using the general thrust equation.
Rockwell Hardness Conversion Calculator
Convert Rockwell C hardness (HRC) to Vickers (HV), Brinell (HB) and tensile strength (MPa) per ASTM E140 for non-austenitic steels.
Rolling Resistance Calculator
Calculate rolling resistance force (N), power required (kW) and energy use per 100 km from mass, speed and rolling resistance coefficient.
Root Mean Square Velocity Calculator
Calculate the RMS velocity, mean speed and most probable speed of ideal gas molecules from temperature and molar mass using the kinetic theory formula.
Rope Tension Calculator
Calculate the tension in a rope or cable holding a mass at any angle, with optional upward or downward acceleration of the system.
Rotational Stiffness Calculator
Calculate rotational (torsional) stiffness k_r = T/θ directly from torque and angle, or from shaft geometry using k_r = G·J/L.
Rydberg Equation Calculator
Calculate the wavelength, photon energy and wavenumber of hydrogen spectral transitions using the Rydberg equation for any n₁ and n₂.
Saponification Value Calculator
Calculate the saponification value (mg KOH/g) of an oil and the exact grams of NaOH or KOH needed for cold-process soap making.
SCFM Calculator
Convert actual flow rate (ACFM) to standard cubic feet per minute (SCFM) using actual pressure and temperature. Also outputs SCMH.
史瓦西半径计算器
根据质量计算黑洞的事件视界(史瓦西)半径。
二级反应计算器
应用二级积分速率方程求半衰期和随时间变化的浓度。
Section Modulus Calculator
Calculate the elastic and plastic section modulus and moment of inertia for rectangular or circular cross-sections.
Sensible Heat Calculator
Calculate sensible heat transferred to or from a substance using Q = m · c · ΔT. Outputs kJ, J, kcal and BTU.
Serial Dilution Calculator
Calculate the final concentration after any number of serial dilution steps using transfer volume, total tube volume and initial concentration.
Series & Parallel Inductors Calculator
Calculate total inductance for 2–4 inductors in series or parallel, plus inductive reactance at a given frequency.
Shaft Size Calculator
Calculate the minimum solid shaft diameter required to transmit a given torque or power within an allowable shear stress, with recommended standard sizes.
Shannon Diversity Index Calculator
Calculate the Shannon diversity index H' and Pielou's evenness J' from species counts to measure ecological diversity.
Shear Modulus Calculator
Calculate shear modulus G from shear stress and strain (G = τ/γ) or from Young's modulus and Poisson's ratio (G = E / 2(1+ν)).
Shear Strain Calculator
Calculate shear strain γ from lateral displacement and length (γ = Δx/L) or from shear stress and shear modulus (γ = τ/G).
Shear Stress Calculator
Calculate shear stress for direct loading (τ = F/A), fluid viscous shear (τ = μ·dv/dy), or maximum shear in a rectangular beam (τ_max = 1.5·V/A).
Shear Wave Velocity Calculator
Compute shear wave velocity Vs = √(G/ρ) from shear modulus and density, then derive Vs30 from a soil-layer profile and determine ASCE 7-16 seismic site class.
Sheep Gestation Calculator
Calculate the expected lambing date from the breeding (tupping) date. Tracks gestation progress for any sheep breed with an adjustable period of 144–157 days.
Shockley Diode Equation Calculator
Compute diode current from the Shockley equation I = Is·(e^(V/nVT)−1) and plot the I-V curve for any junction temperature.
Signal-to-Noise Ratio (SNR) Calculator
Calculate signal-to-noise ratio in dB from power or voltage levels. SNR = 10·log₁₀(S/N) for power, 20·log₁₀(S/N) for voltage.
Simple Harmonic Motion Calculator
Calculate period, frequency, angular frequency, max velocity, max acceleration and total energy for a spring-mass SHM system.
单摆计算器
根据摆长和重力加速度计算单摆的周期和频率,T=2π√(L/g)。
SiPM Photon Detection Efficiency (PDE) Calculator
Calculate the Photon Detection Efficiency of a Silicon Photomultiplier from quantum efficiency, fill factor, and Geiger trigger probability.
Skin Depth Calculator
Calculate the electromagnetic skin depth in a conductor at any frequency — copper, aluminium, iron, nickel or custom material.
Sled Calculator
Calculate a sled's acceleration, net force, and friction on a slope given mass, angle, and kinetic friction coefficient.
Slenderness Ratio Calculator
Calculate the slenderness ratio λ = KL/r for a structural column. Supports solid/hollow circle, rectangular and HSS sections with AISC end conditions.
Smartphone Projector Calculator
Calculate the wall distance and projected image size for a DIY smartphone projector using the thin-lens equation.
斯涅尔折射定律计算器
应用斯涅尔定律 n1·sinθ1 = n2·sinθ2,求折射角、折射率或临界角。
Soil Bulk Density & Porosity Calculator
Calculate soil bulk density, porosity, void ratio, and optional water content from dry mass, total volume, and particle density.
Solar Panel Calculator
Calculate how many solar panels you need, annual energy production, CO₂ savings, payback period, and 25-year net savings.
Solar Panel Wattage Calculator
Calculate a solar panel's output wattage at any irradiance and temperature, plus daily and annual energy production.
Solenoid Inductance Calculator
Calculate the inductance of a solenoid coil from turns, length, diameter, and core permeability, plus stored energy and flux linkage.
螺线管磁场计算器
根据匝数、长度和电流计算螺线管内部的磁场。
Solution Dilution Calculator
Calculate diluted solution concentrations and volumes using C₁V₁ = C₂V₂ — solve for any of the four variables.
溶液混合计算器
求混合两种不同浓度和体积的溶液后所得的最终浓度。
Sound Absorption Coefficient Calculator
Calculate the sound absorption coefficient α from SPL measurements, or compute total room absorption in metric sabins from α and surface area.
Sound Wavelength Calculator
Calculate the wavelength of a sound wave from its frequency and the speed of sound in air, water, steel, or any custom medium.
Space Travel Calculator
Calculate Earth-frame travel time and ship proper time (time dilation) for interstellar travel at any fraction of the speed of light.
Specific Gas Constant Calculator
Calculate the specific gas constant Rₛ for any gas from its molar mass, and find gas density and specific volume at any temperature and pressure.
Specific Gravity Calculator
Calculate specific gravity from known density or by the Archimedes method (weighing in liquid), with density and buoyancy results.
比热容(Q = mcΔT)计算器
使用 Q = mcΔT,结合质量、比热容和温度变化,计算改变物质温度所需的热能。
Specific Impulse Calculator (Isp)
Calculate rocket specific impulse (Isp) from thrust and mass flow rate, plus effective exhaust velocity and achievable delta-v.
Speed of Light Calculator
Calculate the speed of light in any medium via refractive index, and find the travel time of light over any distance.
Speed of Sound Calculator
Calculate the speed of sound in air at any temperature and find the Mach number of any moving object.
Speed of Sound in Solids Calculator
Calculate the longitudinal sound speed in steel, aluminium, glass, concrete, wood and other solids using Young's modulus and density.
Speeds and Feeds Calculator
Calculate spindle RPM and feed rate for CNC milling from cutting speed, cutter diameter, chip load and number of flutes — imperial or metric.
Sphere Density Calculator
Calculate the density of a sphere from its mass and radius, or find the mass of a sphere given its radius and material density.
Spherical Capacitor Calculator
Calculate capacitance, stored charge, and energy of a spherical capacitor from inner and outer shell radii.
Spring Calculator
Calculate spring force (F = kx), elastic potential energy (½kx²), and oscillation period (T = 2π√(m/k)) from spring constant, displacement and mass.
弹性势能计算器
弹簧弹性势能 PE=½kx²,由弹性系数和伸长量求得。
Spring Rate Calculator
Calculate the spring rate (stiffness) of a helical compression or tension spring from wire diameter, coil diameter, active coils and material shear modulus.
Spring Rate Converter
Convert spring rate (stiffness) between N/m, N/mm, kN/m, kN/mm, lb/in, lbf/in, kgf/mm, kgf/m and daN/mm instantly.
标准电池电势计算器
根据阴极和阳极的还原电势计算标准电池电势 E°cell,并判断反应的自发性。
Standard Temperature and Pressure (STP) Calculator
Calculate the volume of any ideal gas at STP or SATP conditions using PV = nRT. Shows molar volume, temperature, pressure and particle count.
Stefan-Boltzmann Law Calculator
Calculate thermal radiation power (P = εσAT⁴) and net heat loss to surroundings using the Stefan-Boltzmann law.
恒星寿命计算器
根据恒星相对于太阳的质量估算其主序阶段的寿命。
恒星光度计算器(Stefan-Boltzmann 定律)
利用 Stefan-Boltzmann 定律,根据恒星半径和表面温度求其光度。
Stiffness Matrix Calculator
Compute the 2×2 element stiffness matrix for a 1D bar or truss element given Young's modulus, cross-section area and length.
化学计量质量换算计算器
利用摩尔比和摩尔质量,将反应物质量换算为产物质量。
Stokes' Law Calculator
Calculate terminal settling velocity and drag force for a sphere in a viscous fluid using Stokes' law (F = 6πηrv).
Stopping Distance Calculator
Calculate vehicle total stopping distance from speed, reaction time and road friction. Shows reaction and braking distance separately.
Stress Calculator
Calculate normal (axial) stress σ = F/A in MPa, elastic strain ε = σ/E, and elongation δ = ε×L for any structural member.
Stress Concentration Factor Calculator (Kt)
Calculate the stress concentration factor Kt for an elliptical hole in a plate using the exact Inglis solution: Kt = 1 + 2(a/b).
Sun Angle Calculator
Calculate the solar elevation angle and azimuth for any location, date and local time using the simplified NOAA solar position algorithm.
Sunrise Calculator
Calculate the exact local sunrise time for any location and date using the NOAA solar position algorithm.
Sunset Calculator
Calculate the exact local sunset time for any location and date using the NOAA solar position algorithm, with daylight duration.
表面重力计算器
根据行星、卫星或恒星的质量和半径计算其表面重力加速度。
Surface Tension Calculator
Calculate capillary rise height, pressure difference and capillary length for any liquid using Jurin's law and surface tension.
SUVAT Calculator
Solve any two of the five SUVAT kinematic variables (s, u, v, a, t) given the other three — covers all 10 valid combinations.
Swine Gestation Calculator
Calculate the expected farrowing date and gestation progress for pigs. Supports 9 breed-specific gestation lengths from 113 to 116 days.
会合周期计算器
根据两个轨道天体的恒星轨道周期计算它们的会合周期。
Tap Water Calculator
Calculate your household tap water consumption and cost per day, week, month and year from daily litres per person and your water tariff.
TDS Calculator
Convert electrical conductivity (EC) to TDS in ppm and check water quality against EPA and WHO drinking water limits.
Telescope Field of View Calculator
Calculate telescope magnification, true field of view, exit pupil, limiting magnitude and Dawes resolution limit from focal lengths and aperture.
望远镜放大倍率与焦比计算器
根据焦距和口径计算望远镜放大倍率、焦比和出射光瞳。
望远镜分辨率与聚光能力计算器
根据口径求望远镜的角分辨率、聚光能力和极限星等。
终端速度计算器
根据质量、面积、阻力系数和空气密度计算下落物体的终端速度。
理论产量计算器
根据反应物的量、摩尔比和摩尔质量计算产物的理论产量。
Thermal Conductivity Calculator
Calculate steady-state heat transfer rate (W) through any material using Q = k·A·ΔT/d — Fourier's law.
Thermal Diffusivity Calculator
Calculate thermal diffusivity (m²/s) from thermal conductivity, density, and specific heat capacity — plus thermal penetration depth.
Thermal Efficiency Calculator
Calculate the thermal efficiency of a heat engine from heat input and heat rejected, or from work output and heat input.
Thermal Energy Calculator
Calculate thermal energy transferred during temperature change (Q = mcΔT) or phase transitions (Q = mL) with unit conversions.
Thermal Equilibrium Calculator
Find the final equilibrium temperature when two objects at different temperatures are brought into thermal contact, assuming no heat loss.
热膨胀计算器(线性/面积/体积)
根据温度变化和膨胀系数计算线性、面积或体积热膨胀量。
Thermal Resistance Calculator
Calculate thermal resistance of a slab or wall, steady-state heat flow rate, and the SI and imperial R-value for insulation rating.
Thermal Stress Calculator
Calculate the thermal stress in a fully constrained structural member from Young's modulus, expansion coefficient, and temperature change.
Thermodynamic Processes Calculator
Calculate work, heat, and internal energy change for isothermal, isobaric, isochoric, and adiabatic ideal-gas processes with a P-V diagram.
薄透镜与球面镜方程计算器
用 1/f = 1/do + 1/di 求透镜和球面镜的像距、焦距或物距。
Thin Lens Equation Calculator
Solve the thin lens equation for image distance, magnification and image type (real/virtual, inverted/upright) for converging or diverging lenses.
Thin-Film Optics Calculator
Calculate constructive or destructive interference in thin films: optical path difference, reflection enhancement, minimum film thicknesses, and phasor diagram.
Three-Phase Power Calculator
Calculate three-phase apparent, real and reactive power, power factor angle, and phase voltage/current for wye and delta connections.
Thrust-to-Weight Ratio Calculator
Calculate thrust-to-weight ratio (TWR) for rockets and aircraft — find net force and vertical acceleration.
潮汐力计算器
计算远处质量对天体施加的差异潮汐力和加速度。
Titration Calculator
Calculate the unknown concentration of a solution from titration data using C₁V₁ = C₂V₂ with stoichiometric ratio support.
TNT Equivalent Calculator
Convert any energy (joules, kWh, kcal, GJ…) to its TNT equivalent in grams, kilograms, tons, kilotons or megatons.
Ton to kW Converter
Convert tons of refrigeration (TR) to kilowatts (kW), BTU/hr and horsepower — or kW back to TR — for HVAC and air conditioning.
力矩计算器
根据力、力臂和角度计算旋转力矩,τ=rF·sinθ。
Torsional Constant Calculator
Calculate the torsional constant J (polar second moment of area) for solid or hollow circular shafts — used in shear stress and angle-of-twist calculations.
Torsional Spring Calculator
Calculate restoring torque, stored energy and natural oscillation frequency of a torsional spring from its constant, deflection angle and load inertia.
Torsional Stiffness Calculator
Calculate torsional stiffness (GJ/L) and angle of twist for solid circular shafts. Supports steel, aluminium, copper and titanium, with shear stress output.
Transformer Sizing Calculator
Find the required kVA rating, turns ratio and primary/secondary line currents for a single- or three-phase power transformer.
变压器匝数比计算器
根据原边参数计算理想变压器的副边电压、电流和匝数比。
Transistor Biasing Calculator
Analyse voltage-divider bias for a BJT NPN transistor: find IC, IB, IE, VCE, VB, VE and transistor power dissipation.
Tree Age Calculator
Estimate a tree's age from its trunk circumference or diameter using the species-specific growth-factor method used by ISA-certified arborists.
Tree Benefits Calculator
Estimate the annual and lifetime environmental benefits of trees: CO₂ sequestration, stormwater interception, energy savings, and air quality improvement.
Tree Diameter Calculator
Convert trunk circumference to diameter at breast height (DBH) and calculate basal area — the standard forestry size measurement.
Tree Height Calculator
Estimate tree height from a measured horizontal distance and angle of elevation using basic trigonometry — no climbing required.
Tree Leaves Calculator
Estimate the number of leaves on a tree using the Leaf Area Index (LAI) method — a standard ecological technique used in forest science.
Tree Spacing Calculator
Calculate trees per hectare or acre for square grid and triangular planting patterns, and estimate total trees for a given plot size.
Tree Value Calculator
Estimate a tree's appraised value using the CTLA trunk formula: trunk area × unit price × species, condition, and location ratings.
Trihybrid Cross Punnett Square Calculator
Calculate offspring phenotype and genotype probabilities for a trihybrid cross involving three independent gene loci.
True Airspeed Calculator (TAS from IAS)
Convert indicated airspeed (IAS) to true airspeed (TAS) using the ISA atmosphere model with optional outside air temperature correction.
True Strain Calculator
Calculate true (logarithmic) strain from initial and final lengths or from engineering strain. ε_true = ln(L/L₀) = ln(1 + ε_eng).
Turtle Tank Size Calculator
Calculate the minimum aquarium size for pet turtles based on shell length using the standard 10-gallons-per-inch rule.
Twist Rate Calculator
Calculate the minimum rifle barrel twist rate to stabilise a bullet using the Greenhill formula, based on bullet diameter, length and muzzle velocity.
Two-Photon Absorption (TPA) Calculator
Calculate the TPA coefficient β, transmittance, and excitation rate for a nonlinear optical material given the cross-section, concentration and laser parameters.
UFO / Relativistic Space Travel Calculator
Calculate how long it takes to travel to the Moon, Mars, Alpha Centauri or any destination at a fraction of the speed of light — with time dilation.
万有引力计算器
牛顿万有引力定律,两质量间的引力 F=Gm₁m₂/r²。
Universe Expansion Calculator
Calculate how fast a galaxy recedes using Hubble's law (v = H₀ × d). Adjust H₀ to explore the Hubble tension.
Valve Flow Coefficient (Cv) Calculator
Calculate the valve flow coefficient Cv, flow rate (GPM), or pressure drop for incompressible liquids using the ISA/ANSI standard formula.
Van der Waals Equation Calculator
Solve the van der Waals real-gas equation (P + an²/V²)(V − nb) = nRT for pressure, temperature or volume with pre-set gas constants.
Vapor Pressure Calculator
Calculate the vapor pressure of common compounds at any temperature using the Antoine equation with NIST/Stull 1947 constants.
Vapor Pressure Deficit (VPD) Calculator
Calculate vapor pressure deficit (VPD) for air and leaf surface from temperature and relative humidity — with plant growth zone indicator.
Vapour Pressure of Water Calculator
Calculate the saturation vapor pressure of water at any temperature (−100 to 374 °C) using NIST Antoine equations and the Sonntag ice-surface formula.
Vegan Footprint Calculator
Estimate your annual diet carbon footprint from animal products and see how much CO₂e you could save by switching to a fully plant-based diet.
Vegetable Seed Calculator
Calculate how many vegetable seeds to sow to reach your target plant count, based on germination rate and packet size.
Vegetable Yield Calculator
Estimate how many vegetables your garden plot will produce based on area, plant spacing, and expected yield per plant.
速度计算器
使用 v = d / t 根据距离和时间计算平均速度。即时以米每秒、千米每小时和英里每小时给出结果。
Vickers Hardness Number Calculator (HV)
Calculate the Vickers Hardness Number (HV) from the applied test force and the mean diagonal of the indentation.
Virtual Temperature Calculator
Calculate the virtual temperature of moist air from dry-bulb temperature, relative humidity and station pressure.
Voltage Divider Calculator
Calculate the output voltage of a two-resistor voltage divider (loaded or unloaded), plus quiescent current, power dissipation, and Thevenin resistance.
Voltage Drop Calculator
Calculate the voltage drop across a cable run from conductor material, cross-section, length and current, with NEC / IEC compliance guidance.
Voltage Regulation Calculator
Calculate voltage regulation percentage for transformers, generators and power supplies from no-load and full-load terminal voltages.
Volts to Electron-Volts Calculator
Convert an accelerating voltage to particle energy in electron-volts (eV, keV, MeV, GeV) and joules for any charge number.
Volume to Density Calculator
Calculate the density of a material from its mass and volume, with unit conversion for mass (kg, g, lb, oz) and volume (m³, L, ft³, in³).
Volume to Mass Calculator
Convert any volume to mass (weight) using density. Choose a common material or enter a custom density in g/cm³.
Von Mises Stress Calculator
Calculate von Mises equivalent stress from principal and shear stresses, compare to yield strength and find the safety factor.
VSWR Calculator
Calculate VSWR, reflection coefficient, return loss, mismatch loss and reflected/delivered power from any RF impedance input.
Warp Speed Calculator
Convert Star Trek warp factors to multiples of the speed of light and calculate travel times to real star systems.
Wastewater Calculator
Calculate BOD removal efficiency, organic loading rate, hydraulic retention time, and volumetric BOD loading for wastewater treatment plants.
Water Demand Calculator
Calculate average daily demand, peak day demand, peak hour flow, and the total design supply needed (including non-revenue water losses) for a municipal water supply system.
Water Density Calculator
Calculate the density of pure water (kg/m³) at any temperature from 0 to 100 °C using the Kell (1967) polynomial, and see how density varies with temperature on a curve.
Water Hardness Calculator
Convert water hardness between ppm (mg/L as CaCO₃), grains per gallon, German, French and English degrees and get soft/hard/very-hard classification.
Water Heating Calculator
Calculate the energy (J, kJ, kWh) needed to heat any mass of water and how long it takes given heater power, using q = mcΔT.
Water Potential Calculator (ψ = ψs + ψp)
Calculate total water potential in plants from solute potential (ψs = −iCRT) and pressure potential (ψp) in MPa.
Water Pressure at Depth Calculator
Calculate absolute and gauge hydrostatic pressure at any depth in fresh water, seawater, or mercury using P = P₀ + ρgh.
Water Viscosity Calculator
Calculate dynamic viscosity (cP/mPa·s) and kinematic viscosity (cSt) of liquid water at any temperature using the Vogel equation.
Water-Soluble Fertilizer Calculator
Calculate how much water-soluble fertilizer to dissolve in a tank to reach a target nutrient concentration in g/L or ppm (mg/L).
Watt Calculator
Calculate electrical power in watts from any two of voltage, current or resistance using P = V × I, P = V²/R or P = I²R.
Watt Converter
Convert watts to kilowatts, megawatts, horsepower, BTU/h, and more power units instantly.
Watt-Hours Calculator
Calculate watt-hours and kWh from power and time. Optionally add your electricity tariff to get cost.
Wattage to Amperage Calculator
Convert watts to amps for DC, single-phase AC, and three-phase AC circuits — includes power factor.
Watts to Amps Calculator
Convert watts to amps (DC): I = P ÷ V. Enter power and voltage to find current and equivalent resistance.
Watts to Heat Calculator
Convert electrical watts to heat output in BTU/h, kcal/h, cal/s, J/s, or MJ/h with optional efficiency.
Watts to Lux Calculator
Convert lamp watts to lux using luminous efficacy and room area. Includes foot-candle output and utilization factor.
波速(v = fλ)计算器
使用 v = f × λ 求波速、频率或波长。输入任意两个值即可求解第三个。
Wave Velocity Calculator
Calculate wave velocity, wavelength, period and wavenumber for sound or EM waves in common media using v = f × λ.
波长计算器
使用 λ = v / f 根据波速和频率计算波长。适用于光波、声波和无线电波,结果以米、厘米和纳米给出。
Wavelength to Energy Calculator
Convert any electromagnetic wavelength to photon energy in joules and eV using E = hc/λ. Supports nm, μm, Å and more.
Wavelength to Frequency Calculator
Convert wavelength to frequency for light, radio, or any wave using f = v/λ. Supports nm to km and Hz to THz output.
Wavenumber Calculator
Convert wavelength to spectroscopic wavenumber (cm⁻¹) or angular wavenumber k = 2π/λ (rad/m). Supports nm, μm, Å, and more.
重力计算器
将质量转换为地球、月球、火星及其他天体上的重力 W=mg。
其他星球重力计算器
了解你在月球、火星、木星及太阳系其他所有星球上的重力。
Wet-Bulb Temperature Calculator
Calculate wet-bulb temperature and dew point from air temperature and relative humidity using the Stull (2011) formula — plus heat stress classification.
Wheatstone Bridge Calculator
Calculate unknown resistance using the balanced Wheatstone bridge formula: Rx = R2 × R3 ÷ R1. Enter the three known resistors and optional supply voltage.
维恩位移定律计算器(峰值波长)
根据黑体温度求其峰值辐射波长,反之亦然。
Wind Correction Angle Calculator
Calculate the wind correction angle and ground speed for a given true course, airspeed, wind direction and wind speed.
Wind Load Calculator
Calculate the wind force on a structure using dynamic pressure and drag coefficient. Covers flat plates, buildings, cylinders and more.
Wind Turbine Power Calculator
Calculate the power output and annual energy production of a wind turbine using the Betz limit, rotor size, wind speed and power coefficient.
Wind Turbine Profit Calculator
Calculate annual revenue, payback period, lifetime ROI and levelised cost of energy (LCOE) for a wind turbine project.
Wing Loading Calculator
Calculate wing loading (N/m² or lb/ft²) and estimate the minimum stall speed for any aircraft or glider wing.
Wire Gauge Calculator
Convert any AWG wire gauge to diameter (mm/in), cross-section area and DC resistance for copper, aluminum, silver or gold.
Wire Resistance Calculator
Calculate the DC resistance of any wire from its length, diameter and material, with temperature correction for copper, aluminium, silver, gold, iron and nichrome.
Wire Size Calculator
Find the correct AWG or kcmil wire gauge for any load current using NEC 310.15 ampacity tables, with voltage-drop check for copper or aluminium.
Find the minimum wire cross-section (mm²/AWG) to keep voltage drop within the IEC/NEC limit for any DC or AC circuit.
Work and Power Calculator
Calculate mechanical work (joules) and average power (watts) from force, displacement and angle using W = F·d·cos θ and P = W/t.
功计算器
使用 W = F·d·cos(θ) 根据力、距离以及它们之间的夹角计算机械功。结果以焦耳、千焦和千卡给出。
动能定理计算器
净功作为动能变化 W=½m(v²−u²),由质量和速度求得。
y⁺ Calculator
Calculate the first-cell height for a target y⁺, or find the actual y⁺ for a given wall-mesh layer — for CFD turbulence modelling.
Young-Laplace Equation Calculator
Calculate the pressure difference across a curved fluid interface using the Young-Laplace equation for droplets, soap bubbles and cylinders.
Young's Modulus Calculator
Calculate Young's modulus from force, area, original length and extension — or solve for force or extension given the material modulus.
Zero-Waste Christmas Tree Calculator
Compare the carbon footprint of a real vs. artificial Christmas tree and find how many years the artificial tree needs to break even.