All calculators & converters

Find the determinant, trace, rank, eigenvalues and inverse of any 2×2 matrix in one step, with an animated transformation.

Find the amplitude, period, phase shift, and vertical shift of a sinusoid y = A sin(Bx + C) + D.

Calculate the bitwise AND of two integers and see the result in decimal, binary, and hexadecimal.

Calculate the antilogarithm (inverse log) of any value in any base: find b^x, 10^x (antilog₁₀), and e^x (antiln).

Calculate the arc length of a curve y = f(x) between x = a and x = b.

Calculate arccos(x) — the inverse cosine of a value — in both degrees and radians. Input must be in [−1, 1].

Calculate arcsin(x) — the inverse sine of any value between −1 and 1 — in both degrees and radians.

Calculate arctan(x) — the inverse tangent of any real number — in degrees and radians, with the complementary arccot.

Compute the area enclosed between two functions f and g over an interval [a,b].

Compute the area under a curve between a and b using accurate numerical integration.

Find the mean of any list of numbers, plus the sum, count, minimum and maximum.

Compute the average rate of change (secant slope) of a function between two x-values a and b.

Find the average value of a function on an interval [a,b] using the mean value of integrals.

Add, subtract, multiply, divide, mod or exponentiate huge whole numbers with exact big-integer precision.

Rotate an integer left or right by k bits within a fixed width. Bits leaving one end wrap around to the other.

Set, clear, toggle, or test a single bit at position k in an integer using bitmask operations.

Shift an integer left or right by k bits, logical or arithmetic. Shows the shifted value in decimal, binary, and hex.

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.

Compute bitwise AND, OR, XOR, NOT (and NAND/NOR/XNOR) on two integers. See the result in decimal, binary, and hex.

Build the truth table for two boolean variables under a chosen operator (AND, OR, XOR, NAND, IMPLIES, IFF).

Compute the n-th Catalan number, counting balanced parentheses, binary trees, paths and triangulations.

Generate the Collatz (3n+1) sequence for any starting number and count the steps to reach 1.

Calculate combinations nCr - the number of ways to choose r items from n when order does not matter.

Count multiset selections: choose r items from n types with repetition allowed, C(n+r-1, r).

Calculate the cosine of any angle in degrees or radians — plus sine, tangent and cotangent, instantly.

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.

Calculate cosh(x) — the hyperbolic cosine — plus sinh(x) and tanh(x), with a graph of the characteristic catenary curve.

Calculate the cotangent cot(θ) = cos(θ)/sin(θ) in degrees or radians — with sin, cos, tan and a graph of the cotangent function.

Find positive and negative coterminal angles for any given angle by adding or subtracting full rotations.

Calculate volume, total surface area, lateral surface area, space diagonal and face diagonals of a cuboid (rectangular box) from length, width and height.

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.

Calculate the area, perimeter, circumradius, inradius, and diagonals of a regular decagon (10-sided polygon) from any known measurement.

Convert fractions to decimals (including repeating decimal detection) and decimals to simplified fractions, with step-by-step working.

Evaluate the definite integral of common functions from a to b using exact antiderivatives.

Convert angles between degrees and radians instantly, with the result also shown as a clean multiple of pi.

Add up the digits of any number and find its digital root by repeated digit summation.

Compute the directional derivative of f(x,y) at a point along a chosen direction vector.

Compute Euler's totient phi(n): the count of integers from 1 to n that are coprime to n.

Raise any base to any power with this exponent calculator, supporting negative, fractional and decimal exponents.

Find the prime factorisation, all divisors, number of divisors and sum of divisors for any positive integer up to 1,000,000.

Calculate the factorial n! of any non-negative integer, the product of all whole numbers from 1 up to n.

List all divisors (factors) of a whole number, count them, sum them, and pair each factor with its complement.

Find the nth Fibonacci number, list the sequence up to n terms, and see the running sum.

Expand (ax + b)(cx + d) using the FOIL method with full step-by-step working — First, Outside, Inside, Last — and get the simplified polynomial.

Add, subtract, multiply or divide two fractions and get the simplified result plus its decimal value instantly.

Find the greatest common divisor (GCD/HCF) and least common multiple (LCM) of a list of integers using the Euclidean algorithm.

Find the greatest common divisor of two integers using the Euclidean algorithm, with every step shown.

Find the greatest common factor (GCF) of two or more integers — lists all common factors and simplifies fractions.

Find the gradient vector and its magnitude for a two-variable function at a point.

Count the edges of a complete graph on n vertices: the handshake number n(n-1)/2 for undirected or n(n-1) directed.

Find the Hamming distance between two equal-length binary (or hex) strings: the number of positions where the bits differ.

Add or subtract two hexadecimal or binary numbers and see the result in hex, binary, and decimal at once.

Calculate arcsin, arccos, or arctan of a value and get the resulting angle in both degrees and radians.

Apply the law of cosines to find a triangle's third side from two sides and the included angle, or an angle from three sides.

Use the law of sines to find a missing side or angle of a triangle from known side-angle pairs.

Find the Least Common Denominator (LCD) of two or three fractions instantly, with step-by-step multipliers and a visual breakdown.

Find the Least Common Multiple (LCM) of two or three integers using the GCD / Euclidean algorithm, with step-by-step working.

Estimate the limit of a function as x approaches a value by numerically probing both sides.

Compute the logarithm of any positive number in any base, plus the natural log (ln) and common log (log₁₀).

Validate any credit card, IMEI, or ID number using the Luhn algorithm checksum — with a step-by-step walkthrough.

Locate the absolute maximum and minimum of a function on an interval [a,b].

Calculate the arithmetic, geometric and harmonic mean of any list of numbers — enter values separated by commas.

Approximate a definite integral with the midpoint rule using n rectangles under the curve.

Compute (base^exponent) mod m efficiently using fast exponentiation by squaring with big integers.

Find the modular multiplicative inverse of a number, the x where a*x is congruent to 1 mod m.

Find the remainder and quotient of a division, with truncated, floored and Euclidean modulo variants for negatives.

Find a root of a function using Newton's iteration starting from an initial guess.

Calculate the bitwise NOR of two integers — NOT(A OR B) — and see the result in decimal, binary, and hexadecimal.

Spell out any whole number in English words, e.g. 1234 becomes one thousand two hundred thirty-four.

Find the derivative of a function at a point using the central difference method, no symbolic algebra needed.

Encode a signed integer in sign-magnitude, one’s-complement, and two’s-complement at a chosen bit width, side by side.

Compute the bitwise OR of two integers in decimal, binary or hex, with a full bit-by-bit breakdown.

Compute the even and odd parity bit for a binary word and count its 1 bits for error-detection checks.

Compute numeric partial derivatives of a two-variable function f(x,y) at a point.

Generate any row of Pascal's triangle - the binomial coefficients C(n,k) for k = 0 to n.

Calculate percent increase or decrease between an old and new value, plus the absolute difference.

Work out percentages fast: X% of Y, what percent one number is of another, and percentage change.

Check if a number is perfect, abundant or deficient by comparing it to the sum of its proper divisors.

Calculate permutations nPr = n!/(n-r)! - the number of ordered arrangements of r items chosen from n.

Count arrangements when repetition is allowed: n^r ordered selections of r positions from n symbols.

Approximate π using Nilakantha, Gregory–Leibniz or Machin series — see convergence, error and correct decimal places for any number of terms.

Apply the pigeonhole principle: find the guaranteed minimum in the fullest box and how many items force a target count.

Convert polar coordinates (r, theta) to rectangular (x, y) coordinates and plot the resulting point.

Count the set bits (Hamming weight) and bit length of an integer, and check if it is a power of two.

Explore the Potato Paradox: calculate how much weight a batch loses when its water percentage drops slightly.

Find the number of subsets in the power set of an n-element set: 2^n total, plus proper and non-empty subset counts.

Break any integer into its prime factors and show the exponent form, e.g. 360 = 2^3 x 3^2 x 5.

Check whether any integer is prime and see its prime factorization using fast trial division up to the square root.

Solve proportions of the form a:b = c:d for the missing value, and simplify any ratio to its lowest terms.

Convert rectangular (x, y) coordinates to polar form (r, theta) using magnitude and the atan2 angle.

Compute the reference angle for any angle and see which quadrant it lands in, in degrees or radians.

Calculate left, right, or midpoint Riemann sums for a function over an interval.

Solve a right triangle from any two known values: legs, hypotenuse, or an acute angle, with area and perimeter.

Find the square root, cube root or any nth root of a number, including real odd roots of negative values.

Round any number to a chosen number of decimal places or to the nearest 10, 100 or 1000, with floor and ceiling values.

Generate RSA public and private keys from two primes, then encrypt and decrypt an integer message — step by step.

Convert decimal numbers to scientific notation and back, showing the mantissa, exponent and standard form.

Calculate sec(θ) — the secant function — in degrees or radians, plus all six trig function values at the same angle.

Find the second derivative of a function at a point and tell whether it is concave up or down.

Compute union, intersection, difference and symmetric difference of two sets you enter, with element counts.

Approximate a definite integral with Simpson's rule (parabolic arcs) for high accuracy.

Calculate sin(θ), cos(θ), tan(θ) and cot(θ) for any angle in degrees or radians instantly.

Find sine, cosine, tangent and their reciprocals for any angle in degrees or radians in one step.

Calculate sinh(x), cosh(x), tanh(x) and coth(x) for any real x. Verifies the identity cosh²−sinh²=1 and plots the curve.

Compute Stirling numbers of the second kind S(n,k): partitions of n items into k non-empty subsets.

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.

Find the surface area generated by revolving a curve about the x-axis between a and b.

Compute singular values, condition number, rank, Frobenius norm and spectral norm of a 2×2 matrix via SVD.

Calculate tan(θ) for any angle in degrees or radians — plus sin, cos, cot, sec and csc, with a plotted tangent curve.

Get the equation of the tangent line to a function at a chosen point x = a.

Calculate tanh(x) — the hyperbolic tangent — plus sinh(x), cosh(x) and the derivative sech²(x), with the characteristic S-curve plot.

Evaluate a Taylor polynomial of a function centered at c and compare it to the true value.

Calculate sin, cos, tan, cot, sec and csc for any angle θ in degrees or radians, with quadrant and reference angle.

Estimate the area under a curve with the trapezoidal rule using n subintervals.

Compute the nth triangular number (1+2+...+n) and view the sequence of triangular numbers.

Calculate all six trigonometric functions — sin, cos, tan, csc, sec, cot — for any angle in degrees or radians.

Evaluate both sides of a chosen trig identity at a given angle to numerically verify it holds.

Convert signed decimal to two's-complement binary and back, at 8, 16, 32, or 64 bits. Shows representable range.

Get the exact (cos, sin) coordinates on the unit circle for any angle and plot the point on the circle.

Calculate 2D vector magnitude, dot product, 2D cross product, angle between vectors and resultant sum — with an animated vector diagram.

Find the volume of a solid formed by revolving a curve about the x-axis (disk method).

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.

Find the eigenvalues of a 2x2 matrix from its characteristic equation. Enter the four entries to get real or complex roots.

Solve |ax+b|=c for x and graph y=|ax+b| against y=c to see the intersection points.

Find the angle between two vectors using the dot product formula. Enter components to get the angle in degrees and radians.

Find the nth term and the sum of an arithmetic sequence from the first term and common difference.

Expand (a+b)^n with the binomial theorem and list every term coefficient.

Find the cofactor matrix and adjugate (adjoint) of a 2x2 or 3x3 matrix. Enter rows of numbers to get both matrices.

Rewrite ax^2+bx+c in vertex form a(x-h)^2+k and read off the vertex.

Solve a 2x2 or 3x3 system of linear equations with Cramer’s rule using determinants. Enter coefficients and constants.

Compute the cross product of two 3D vectors. Enter three components each to get the perpendicular vector and its magnitude.

Solve ax^3+bx^2+cx+d=0 for all real and complex roots, with the cubic curve graphed.

Find the constant of variation k and predict a new value using direct or inverse proportionality.

Find the discriminant b^2-4ac of a quadratic and instantly see how many real roots it has.

Calculate the straight-line distance between two points (x₁, y₁) and (x₂, y₂) using the distance formula derived from the Pythagorean theorem.

Calculate the dot (scalar) product of two vectors of equal length. Enter components separated by spaces or commas.

Factor ax^2+bx+c into a(x-r1)(x-r2) using its roots, with real or complex output.

Compose two linear functions f and g and evaluate (f∘g)(x) at a point.

Compute the nth term, finite sum, and infinite sum of a geometric sequence from its ratio.

Apply exponent laws to same-base powers: multiply, divide, or raise to a power and simplify.

Find the equation of a line from two points — slope-intercept (y = mx + b), point-slope and standard form, plus the slope and intercepts, with a graph.

Compute a linear combination c1*v1 + c2*v2 + ... of several vectors. Enter vectors as rows and matching scalar coefficients.

Solve any linear equation of the form ax + b = 0 for x instantly. Free step-by-step linear equation calculator with edge-case handling.

Solve a one-variable linear inequality ax+b (</<=/>/>=) c and view the solution region on a number line.

Add two matrices of the same size element by element. Enter each matrix as rows of space-separated numbers and get the resulting matrix instantly.

Compute the determinant of a 2x2 or 3x3 matrix entered as rows of numbers; auto-detects the size.

Find the inverse of a 2x2 or 3x3 matrix using the determinant and adjugate. Enter rows of numbers; must be non-singular.

Multiply two matrices using the row-by-column dot product rule. Enter both matrices as rows of numbers; sizes must be compatible.

Raise a square matrix to an integer power. Enter the matrix as rows of numbers and an exponent to compute A to the n.

Find the rank of any matrix using Gaussian elimination. Enter rows of numbers to count the independent rows (nonzero pivots).

Subtract one matrix from another element by element. Enter both matrices as rows of numbers and see the difference matrix with each step.

Calculate the trace of a square matrix: the sum of its main diagonal entries. Enter the matrix as rows of numbers.

Find the transpose of any matrix by flipping rows and columns. Enter rows of space-separated numbers and get A-transpose instantly.

Find the midpoint between two points (x₁, y₁) and (x₂, y₂) on the coordinate plane. Free midpoint formula calculator showing both x and y coordinates.

Find the quadratic equation y = ax² + bx + c of the parabola through three points, plus its vertex, axis of symmetry and discriminant, with a graph.

Find the equations of the lines parallel and perpendicular to a given slope that pass through a point, in slope-intercept form, with a graph.

Decompose (px+q)/((x-r1)(x-r2)) into A/(x-r1)+B/(x-r2) for distinct linear factors.

Calculate percent error between a measured value and the actual (true) value. Free percentage error calculator for science labs, chemistry, and physics.

Write the equation of a line from a point and a slope using point-slope form y − y₁ = m(x − x₁), then convert to slope-intercept and standard form, with a graph.

Evaluate any polynomial P(x) at a given x value using Horner's method, with the curve plotted around the point.

Solve a proportion a/b = c/x for the unknown x using cross multiplication. Free proportion and ratio solver for equivalent fractions.

Solve right triangles with the Pythagorean theorem. Find the hypotenuse from two legs, or a missing leg from the hypotenuse and one leg.

Solve ax² + bx + c = 0 with the quadratic formula — real and complex roots, plus the discriminant.

List every possible rational root of a polynomial from its constant and leading coefficients.

Reduce any matrix to reduced row echelon form with Gauss-Jordan elimination. Enter rows of numbers to see the RREF.

Multiply a matrix by a scalar. Enter the matrix as rows of numbers and a scalar value to scale every entry instantly.

Compute the scalar triple product of three 3D vectors and the volume of the parallelepiped they form.

Find the slope of a line between two points, plus the angle of inclination and y-intercept. Free slope and rise-over-run calculator with the line equation.

Divide a polynomial by (x-c) using synthetic division to get the quotient and remainder.

Solve a 2x2 system of linear equations using Cramer’s rule. Enter coefficients to find x and y instantly, with determinant and edge-case detection.

Normalize a vector to length 1. Enter the components and get the unit vector pointing in the same direction plus its magnitude.

Find the magnitude (length/norm) of a vector in any dimension. Enter components separated by spaces or commas to get |v|.

Project one vector onto another. Enter vectors a and b to get the projection vector and the scalar projection of a onto b.

Calculate the acreage of a rectangular, triangular or circular plot from its dimensions, with results in acres, sq ft, sq m and hectares.

Convert angles between degrees, radians, gradians, arcminutes, arcseconds and turns — instantly and precisely.

Convert area between square meters, square feet, acres, hectares, square miles, square kilometers and more — instantly and accurately.

Convert atmospheres (atm) to pascal, kPa, bar, psi, mmHg, Torr, inHg and millibar — or convert any pressure unit to atm.

Estimate the size of data after Base64 encoding, including the ~33% overhead and optional line-break/data-URI padding.

Convert a decimal number to packed binary-coded decimal and back, encoding each digit as its own 4-bit nibble.

Convert any non-negative integer between binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16) instantly.

Convert digital data sizes between bits, bytes, KB, MB, GB, TB and binary KiB, MiB, GiB, TiB — with the decimal vs binary difference explained.

Convert centimeters to inches, feet, meters, millimeters, yards and miles instantly with a full reference table.

Convert an RGB color (0–255 per channel) to HEX, HSL, HSV and CMYK — with a live color preview swatch.

Convert cooking measurements between teaspoons, tablespoons, fluid ounces, cups, pints, quarts, milliliters and liters.

Convert typing speed between characters per second (CPS), words per minute (WPM), CPM, and keystrokes per hour (KPH).

Calculate cubic feet from length, width and height in feet. Instantly converts to cubic yards, cubic inches, cubic meters, liters and US gallons.

Calculate cubic meters from length, width and height in meters. Converts to liters, cubic feet, cubic inches, cubic centimeters and gallons.

Convert between major world currencies with live, daily-updated exchange rates.

Convert bytes, KB, MB, GB, TB and binary KiB, MiB, GiB units accurately.

Convert data transfer rates between bits per second, kbit/s, Mbit/s, Gbit/s and bytes, KB/s, MB/s, GB/s instantly.

Compute real-world transfer time for a dataset over a link, factoring protocol/overhead efficiency to get effective throughput.

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.

Convert decimetres (dm) to and from millimetres, centimetres, metres, kilometres, inches, feet, yards, and miles.

Convert density between kg/m3, g/cm3, g/ml, kg/L, lb/ft3 and lb/in3 quickly and accurately for science and engineering.

Estimate how long a file takes to download from its size and your connection speed, with a clean hh:mm:ss result.

Swap the byte order of a 16/32/64-bit hex value to convert between big-endian and little-endian.

Convert energy between joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, BTU, foot-pounds and electronvolts.

Convert Fahrenheit to Celsius, Kelvin and Rankine instantly with exact formulas and a visual temperature scale.

Convert feet to meters, inches, centimeters, millimeters, yards, miles, kilometers, and nautical miles instantly with exact values.

Convert force between newtons, kilonewtons, dynes, pound-force, kilogram-force and ounce-force quickly and accurately.

Convert frequency between hertz, kilohertz, megahertz, gigahertz, terahertz and revolutions per minute (rpm) instantly.

Convert fuel economy between L/100km, kilometers per liter, US miles per gallon and UK miles per gallon accurately.

Convert US liquid, US dry or Imperial gallons to litres, millilitres, quarts, pints, cups, fluid ounces and cubic units.

Convert any English word or phrase to a gematria number value using Simple (A=1–Z=26), Reverse, or Reduced systems.

Convert between standard binary and reflected Gray code, where adjacent values differ by exactly one bit.

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.

Convert height between centimetres and feet & inches. Switch direction to go cm → ft/in or ft/in → cm, with the value in metres. Free, instant and accurate.

Convert a hex color code (#RGB or #RRGGBB) into red, green and blue channel values and a CSS rgb() string.

Convert hours to minutes, seconds, milliseconds, days, weeks, months and years instantly. Supports decimal hours (e.g. 1.5 h).

Break a decimal number into IEEE-754 sign, exponent, and mantissa bits for 32-bit (single) and 64-bit (double) precision.

Convert between imperial (inches, feet, pounds, gallons, °F) and metric units instantly — all four measurement types in one tool.

Convert inches to millimetres, centimetres, metres, feet, yards and miles instantly using exact SI definitions.

Convert kilometres to miles, metres, feet, yards, inches, nautical miles and light-years — or convert any distance to kilometres.

Convert kilopascals (kPa) to pascals, MPa, bar, atm, psi, mmHg, Torr, inHg and mbar — or convert any pressure unit to kPa.

Convert land area between acres, hectares, square meters, square feet, sq km, sq miles, rai, cents and marla instantly.

Convert normal text into leet speak (1337) by substituting letters with numbers and symbols — basic or advanced mode.

Convert between meters, kilometers, miles, feet, inches, yards and more — instantly and accurately.

Convert Bulgarian leva to euro (and back) at the official irrevocably fixed changeover rate of 1 EUR = 1.95583 BGN, with the legally required rounding.

Convert between litres, cubic centimetres (cc), millilitres and US gallons — plus fl oz and cups in one step.

Convert Mbps to MB/s, KB/s and Gbps, and calculate how long it takes to download or upload any file at your speed.

Convert mils (thousandths of an inch) to micrometers, millimeters, centimeters, meters and inches instantly.

Convert miles to kilometers, meters, feet, yards, nautical miles and centimeters instantly with exact international conversion factors.

Convert millimeters to inches, centimeters, meters, micrometers, feet, yards and miles instantly with exact conversion factors.

Convert inches, feet, yards, centimeters, meters, kilometers or micrometers to millimeters instantly with exact conversion factors.

Convert megapascals (MPa) to psi, bar, kPa, atm, GPa, Torr, mmHg and more — or convert any pressure unit to MPa.

Convert torque between Newton-meters, foot-pounds, inch-pounds, kgf·m and Newton-centimeters instantly.

Convert nanometres to micrometres, millimetres, metres, angstroms and picometres — or convert any of those back to nm.

Convert any whole number between binary, octal, decimal and hexadecimal. Enter a value, pick its base, and see all four representations instantly.

Calculate how many sheets of paper and reams to buy for a print job — supports duplex printing and multiple paper sizes.

Convert pounds and ounces to kilograms, grams, stones and total ounces. Enter lb + oz together for a combined weight.

Convert power between watts, kilowatts, megawatts, horsepower, metric horsepower, BTU per hour and foot-pounds per second.

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.

Convert pressure between pascals, kilopascals, megapascals, bar, psi, atmospheres, mmHg and torr — fast and accurate.

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.

Turn red, green and blue values (0-255) into a #RRGGBB hex code plus a ready-to-use CSS rgb() string.

Convert RGB color channels into HSL (hue degrees, saturation and lightness percent) for easier color tweaking.

Convert numbers to Roman numerals and Roman numerals back to numbers (1–3999), in both directions, using the standard subtractive notation rules.

Convert m/s, km/h, mph, knots and feet per second quickly and accurately.

Convert Celsius, Fahrenheit, Kelvin and Rankine instantly with exact formulas.

Convert time between nanoseconds, microseconds, milliseconds, seconds, minutes, hours, days, weeks, months and years instantly.

Convert torque between newton-meters, kilonewton-meters, pound-feet, pound-inches and kilogram-force-meters accurately.

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.

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.

Estimate a video file's size from its bitrate and duration (with optional audio track), or solve for bitrate.

Convert volume between liters, milliliters, cubic meters, US gallons, quarts, pints, cups, fluid ounces, tablespoons and imperial gallons.

Check the contrast ratio between two hex colors and whether it passes WCAG AA/AAA for normal and large text.

Convert kilograms, grams, pounds, ounces, stones and tonnes quickly and accurately.

Convert any distance to obscure and unusual units: smoots, cubits, furlongs, hands, fathoms, chains, leagues and light years.

Convert yards to metres, centimetres, feet, inches, miles, furlongs and more using exact 1959 SI definitions.

Project your 401(k) balance from salary, contribution %, employer match and expected return. Includes employer match modelling.

Project your 403(b) retirement balance for teachers, nurses and non-profit employees, including the 15-year catch-up rule.

Project your 529 college savings plan balance from current balance, monthly contributions and expected return.

Calculate the Average Daily Rate (ADR) for a hotel or rental property, plus occupancy rate and RevPAR from total room revenue.

Calculate AFFO, FFO, AFFO per share, and P/AFFO for REITs — the key metrics for evaluating real estate investment trust cash flow.

Calculate Additional Funds Needed (AFN) for financial planning: how much external financing a company must raise to support its projected sales growth.

Calculate your US Adjusted Gross Income (AGI) by subtracting above-the-line deductions from total gross income.

Calculate your monthly loan payment, total interest and full payoff cost from the loan amount, interest rate and term, with a first-year amortization schedule.

Calculate Average Propensity to Consume (APC) and Average Propensity to Save (APS) from income and spending.

Calculate the true Annual Percentage Rate (APR) of a loan including upfront fees, monthly payment, and total interest cost.

Calculate Annual Percentage Yield (APY) from a nominal interest rate and compounding frequency, including continuous compounding.

Calculate After Repair Value (ARV), net profit and ROI for fix-and-flip real estate. Includes the 70% rule maximum offer price.

Calculate Average Variable Cost (AVC = TVC ÷ Q) and optionally Average Fixed Cost and Average Total Cost from your production figures.

Find the break-even point in units and revenue from your fixed costs, price per unit and variable cost per unit.

Bulgarian net-salary calculator for 2026: flat 10% income tax, social contributions with the insurable-income cap, and the result in both leva and euro at the official fixed rate.

Calculate CAGR from beginning and ending values over any number of years — the smoothed annual growth rate for investments, revenue or any metric.

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).

Work out your monthly car payment, total interest and total cost from the vehicle price, down payment, interest rate and loan term in months.

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.

Calculate customer lifetime value (CLTV) from order value, purchase frequency, lifespan and gross margin, plus LTV:CAC ratio and payback period.

Calculate Cost of Goods Sold using beginning inventory, purchases and ending inventory — plus gross profit and gross margin if you enter revenue.

See how your money grows with compound interest across different compounding frequencies.

Calculate Cost Per Acquisition (CPA) from total ad spend and conversions, plus ROAS and profit when you add total revenue.

Calculate CPM (cost per 1,000 impressions), total ad cost, or total impressions for any digital advertising campaign.

Calculate Click-Through Rate (CTR) from clicks and impressions. Add ad cost to get CPC and CPM alongside your CTR.

Calculate Customer Acquisition Cost by dividing total sales and marketing spend by the number of new customers acquired in the same period.

Calculate net present value (NPV) by discounting annual cash flows at your required return rate. Includes terminal value and payback period.

Calculate how long it takes to pay off a debt and the total interest you will pay, given balance, interest rate, and monthly payment.

Find out how long it takes to pay off a credit card or loan balance with a fixed monthly payment, plus the total interest you will pay along the way.

Find the discount percentage from an original price and a sale price, and see exactly how much money you save.

Calculate the Debt Service Coverage Ratio (DSCR) from net operating income and annual debt payments — used by lenders to assess loan eligibility.

Calculate your Debt-to-Income ratio (DTI) by entering monthly debt payments and gross income — see how lenders assess your borrowing capacity.

Convert a nominal interest rate to the Effective Annual Rate (EAR) for any compounding frequency — daily, monthly, quarterly, or continuous.

Calculate EBIT (Earnings Before Interest and Taxes) from revenue, COGS and operating expenses — with gross margin and EBIT margin.

Calculate EBT (Earnings Before Tax) from revenue, COGS, operating expenses and interest expense — and find the EBT margin.

Calculate the maturity corpus and Section 80C tax savings for an ELSS investment, for both lump sum and monthly SIP modes.

Calculate your monthly EMI, total interest and see the outstanding balance curve for any loan amount, rate and tenure.

Calculate the Expected Monetary Value of a decision by weighting up to three scenarios by their probabilities and monetary outcomes.

Find the Economic Order Quantity (EOQ) that minimises total inventory cost — ordering cost balanced against annual holding cost.

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).

Calculate basic and diluted Earnings Per Share (EPS) from net income, preferred dividends and share counts, plus the P/E ratio.

Calculate FFO, FFO per share, and P/FFO for REITs — the standard NAREIT metric for evaluating real estate investment trust operating performance.

Finnish net-salary calculator for 2026: progressive state tax, municipal tax, church tax, TyEL pension and unemployment insurance — see exactly what stays in hand.

Calculate your FIRE number, years to financial independence, and portfolio growth using the 4 % safe withdrawal rule and compound returns.

Calculate the future value of money using the time value of money. Project a lump sum plus regular contributions with compound growth at any rate, term and compounding frequency.

Calculate GDP using the expenditure approach: GDP = C + I + G + (X − M). See each component's share of total output.

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.

Calculate the Herfindahl-Hirschman Index (HHI) to measure market concentration — enter up to 10 firm market shares to get the index and DOJ classification.

See how inflation raises the future cost of money and erodes the purchasing power of a given amount over a number of years.

Calculate mortgage payments with an interest-only period — monthly payment during and after, total cost, and the remaining-debt curve. Supports Danish realkredit admin margins (bidrag).

Project IRA balance growth to retirement, compare Traditional (pre-tax) vs Roth (post-tax) after-tax values, based on 2025 contribution limits.

Calculate the Liquidity Coverage Ratio (LCR) per Basel III: HQLA divided by 30-day net cash outflows, with inflow cap applied.

Calculate Loss Given Default (LGD), recovered amount, and Expected Loss (EL) from EAD, recovery rate and probability of default.

Calculate your monthly loan payment, total interest, total cost of credit and APR for any loan amount, rate, term and upfront fee.

Calculate your monthly loan EMI, total interest and total repayment for any loan amount, rate and tenure.

Calculate the LTV ratio for a mortgage or home loan, your equity percentage, and whether PMI is likely required.

Calculate your 2024 MAGI for Roth IRA contributions and traditional IRA deductibility — enter AGI plus common add-backs.

Calculate the selling price from a product cost and markup percentage, plus the profit per unit and the resulting profit margin.

Calculate your monthly mortgage payment, total interest and total cost from the loan amount, annual interest rate and loan term in years.

Calculate the Marginal Propensity to Consume (MPC), Marginal Propensity to Save (MPS), and the Keynesian fiscal multiplier from income and spending changes.

Calculate the Marginal Propensity to Save (MPS), MPC, and the Keynesian fiscal multiplier from income and savings changes across two periods.

Calculate Market Value Added (MVA) — the difference between a firm's market capitalisation and book equity — to measure wealth created for shareholders.

Calculate Net Asset Value (NAV) per share for mutual funds, ETFs, or investment companies, plus the premium or discount to market price.

Calculate your net salary after tax with presets for Sweden, Finland, Denmark and Norway — municipal tax, state tax, social contributions and credits, all editable.

Calculate the Net Promoter Score (NPS) from Promoter, Passive, and Detractor counts with a segment breakdown.

Calculate the Net Stable Funding Ratio (NSFR) for Basel III compliance — check whether Available Stable Funding meets Required Stable Funding.

Calculate your full monthly mortgage payment (PITI): Principal, Interest, property Taxes and homeowners Insurance — plus PMI if applicable.

Calculate monthly and annual PMI, your loan-to-value ratio, and when PMI will drop off your mortgage.

Calculate PPF maturity value, total interest earned and corpus growth year by year for any deposit amount, rate and period.

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.

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.

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.

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.

Project your retirement nest egg from your current age, retirement age, current savings, monthly contributions and expected annual return.

Calculate your IRS Required Minimum Distribution (RMD) from a traditional IRA or 401(k) using the 2022 Uniform Lifetime Table.

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.

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.

Calculate Return on Equity (ROE) as net income ÷ average shareholders' equity, with optional DuPont decomposition into margin, turnover and leverage.

Calculate return on investment (ROI) as a percentage, the net gain or loss, and the annualized return over your holding period.

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.

Calculate Return on Sales (ROS): operating profit divided by net revenue, expressed as a percentage — the operating margin.

Calculate the Relative Strength Index (RSI) from average gain and average loss over a period — with overbought/oversold signal zones.

Convert pay between hourly, weekly, monthly and annual figures using your hours per week and weeks per year.

Add sales tax to a price or extract the tax from a tax-included total, showing the net price, the tax amount and the gross price.

See how much your savings will grow with regular monthly deposits and compound interest, including total contributions and interest earned.

Calculate simple interest and the total amount for a principal, rate and time period.

Calculate the maturity value of India's Sukanya Samriddhi Yojana account — annual deposits, compound interest, total interest earned.

Calculate how long your investment corpus lasts with a fixed monthly withdrawal and expected annual return rate.

Estimate your take-home (net) pay from gross income using your own effective tax rate. Country-agnostic: works for any salary, pay frequency and deductions.

Calculate the maturity value and interest of a term (fixed) deposit — compounding monthly, quarterly or yearly, with optional tax on interest.

Calculate OSHA's Total Recordable Incident Rate (TRIR) and benchmark your workplace safety against US industry averages.

Calculate Value at Risk (VaR) and Expected Shortfall (CVaR) for a portfolio using the parametric normal-distribution method at 90–99.9 % confidence.

Add or remove VAT with the 2026 standard rate of any of 30 European countries preloaded — including the new Finnish 25.5%, Estonian 24% and Slovak 23% rates.

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.

Calculate the Ankle-Brachial Index (ABI) from ankle and arm systolic pressures to screen for peripheral arterial disease (PAD).

Calculate your Army Combat Fitness Test (ACFT) score for all six events and see your total out of 600.

Calculate the urine albumin-to-creatinine ratio (ACR) from a spot urine sample to assess kidney health and CKD albuminuria category.

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.

Calculate the Apnea-Hypopnea Index (AHI) from a sleep study and classify sleep apnea severity per AASM guidelines.

Calculate the Absolute Neutrophil Count (ANC) from a CBC differential and classify neutropenia severity.

Calculate the APRI score (AST-to-Platelet Ratio Index) to estimate the probability of liver fibrosis and cirrhosis.

Estimate your blood alcohol concentration (BAC) using the Widmark formula. Enter drinks, weight, sex and time elapsed.

Calculate your Body Adiposity Index (BAI) — an estimate of body fat percentage from hip circumference and height, requiring no scale.

Analyse your basal body temperature (BBT) reading against your follicular baseline to detect the post-ovulation thermal shift and estimate cycle phase.

Calculate Biologically Effective Dose (BED) and EQD2 for any radiation therapy fractionation schedule using the linear-quadratic model.

Estimate Basal Energy Expenditure using the revised Harris-Benedict equation with optional stress and activity factors for clinical nutrition.

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.

Calculate your Body Mass Index (BMI) from height and weight, with the WHO weight category.

Estimate your Basal Metabolic Rate (BMR) and daily calorie needs using the Mifflin-St Jeor equation.

Estimate your body fat percentage with the US Navy circumference method using neck, waist, hip and height measurements in centimeters.

Calculate body surface area (BSA) in square meters from height and weight using the simple and accurate Mosteller formula.

Calculate your Body Roundness Index (BRI) from height and waist circumference — a shape-based body fat estimate that outperforms BMI.

Calculate body surface area (BSA) in m² using the Mosteller, Du Bois, or Haycock formula — with a side-by-side comparison of all three.

Work out the daily calorie target you need to lose weight. Enter your maintenance calories (TDEE) and a weekly goal to get a safe daily intake and deficit.

Estimate calories burned during exercise using MET values from the Compendium of Physical Activities. Pick an activity, enter your weight and duration.

Calculate the age-adjusted Charlson Comorbidity Index (CCI) from patient age and weighted comorbid conditions. Estimates 10-year survival probability.

Estimate the date you conceived from your last menstrual period or your due date, with a likely fertile conception window of a few days.

Estimate creatinine clearance (CrCl) and kidney function stage using the Cockcroft-Gault equation from age, sex, weight, and serum creatinine.

Calculate your daily calorie needs (TDEE) with the Mifflin-St Jeor equation and get target calories to lose, maintain, or gain weight.

Look up the NIH Dietary Reference Intake (RDA/AI) for protein, fibre, vitamins, and minerals by age and sex.

Calculate your estimated due date and current pregnancy week using Naegele's rule, adjusted for your personal cycle length.

Estimate your kidney filtration rate (eGFR) using the CKD-EPI 2021 race-free equation from serum creatinine, age, and sex.

Calculate your new ELO rating and points gained or lost after a match using the standard ELO formula for win, draw, or loss.

Calculate power output, calories burned and distance for a rowing ergometer workout from your 500 m split time using the Concept2 formula.

Estimate how long EtG (ethyl glucuronide) remains detectable in urine after alcohol consumption, based on drinks consumed and time elapsed.

Calculate your daily fat intake in grams from total calories and a fat percentage target, with protein, carb, and saturated fat breakdowns.

Calculate the Front of Center (FOC) percentage for an arrow using length and balance point — essential for tuning accuracy and stability in archery.

Calculate a premature baby's corrected (adjusted) age by subtracting weeks born early from their chronological age.

Find out how many weeks and days pregnant you are from your last menstrual period (LMP), with trimester, estimated due date and days remaining.

Calculate the Glycemic Load (GL) of a food from its Glycemic Index (GI) and carbohydrate content per serving.

Calculate the Glucose Infusion Rate (GIR) in mg/kg/min from dextrose concentration, infusion rate, and patient weight.

Calculate the Glasgow Coma Scale score from eye, verbal, and motor responses to assess level of consciousness.

Calculate your maximum heart rate and the five training zones in beats per minute from your age, for smarter cardio workouts.

Calculate the Hepatic Steatosis Index (HSI) from ALT, AST, BMI, sex and diabetes status to screen for non-alcoholic fatty liver disease.

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.

Calculate the validated ICH Score (0–6) from GCS, hemorrhage volume, IVH, location and age to estimate 30-day mortality risk.

Find your ideal body weight in kilograms from your height and sex using the widely used Devine formula, with a healthy reference range.

Calculate the International Normalized Ratio (INR) from PT, mean normal PT, and ISI — with therapeutic range interpretation for warfarin monitoring.

Calculate the Injury Severity Score (ISS) from AIS region scores to classify trauma severity from minor to unsurvivable.

Estimate LDL cholesterol from Total Cholesterol, HDL and Triglycerides using the Friedewald equation (mg/dL or mmol/L).

Estimate your lean body mass (LBM) in kilograms from weight, height, and sex using the Boer formula, plus approximate fat mass.

Convert daily calories into grams of carbohydrate, protein, and fat for balanced, low-carb, or high-protein diet splits.

Calculate the MCA-PSV Multiple of Median (MoM) for fetal anemia screening using the Mari 2000 formula. For use with specialist guidance.

Convert any opioid dose to morphine milligram equivalents (MME/day) using CDC 2022 conversion factors.

Calculate the Neutrophil-to-Lymphocyte Ratio (NLR) from CBC counts — a rapid blood-test marker for systemic inflammation.

Calculate NNT, NNH, ARR, RRR, Relative Risk and Odds Ratio from control and experimental event rates.

Calculate the real-world noise reduction and protected dBA level from a hearing protector's NRR rating, using NIOSH or EPA methods.

Estimate your one-rep max (1RM) from a set using the Epley formula, plus a percentage chart of training loads (95%–70%) with target rep ranges.

Estimate your ovulation day and fertile window from your last period and cycle length, plus your next expected period date. Free ovulation and fertility calculator.

Predict your next 3 period start and end dates and your estimated ovulation day from your last period and average cycle length.

Interpret a post-void residual (PVR) bladder scan — residual fraction, estimated capacity, and clinical severity category.

Track your pregnancy week by week. Enter your last menstrual period to find your current gestational age, trimester, estimated due date and how far along you are.

Estimate your pregnancy due date with Naegele’s rule from your last menstrual period and cycle length. See gestational age, trimester and conception date.

Calculate the Physiological Strain Index (PSI) from core body temperature and heart rate to quantify heat stress during exercise or occupational heat exposure.

Calculate the heart-rate-corrected QT interval (QTc) using Bazett, Fridericia, Framingham or Hodges formula — with prolongation risk interpretation.

Calculate your Resting Metabolic Rate (RMR) and TDEE using Mifflin-St Jeor or Katch-McArdle — choose based on whether you know your body fat %.

Calculate your running pace in minutes per kilometer, speed in km/h, and pace per mile from a distance and finish time.

Find the best bedtime or wake-up time using 90-minute sleep cycles. Wake between cycles, not mid-cycle, to feel more refreshed and less groggy.

Calculate your bone density T-Score from a DXA scan BMD (g/cm²) and get a WHO classification: normal, osteopenia, or osteoporosis.

Estimate your Total Daily Energy Expenditure (TDEE) from your BMR and activity level using the Mifflin-St Jeor equation, with calorie targets for weight loss, maintenance and gain.

Calculate the IV Alteplase (tPA) dose for acute ischemic stroke: total dose, IV bolus, and 60-minute infusion by patient weight.

Calculate the Urea Reduction Ratio (URR) from pre- and post-dialysis BUN values to assess haemodialysis adequacy against the KDOQI ≥ 65 % target.

Calculate your waist-to-hip ratio (WHR) and see your health risk category based on World Health Organization thresholds for men and women.

Calculate wound area reduction (WAR%) from initial and current wound dimensions to track healing progress and apply the validated 4-week 40% threshold.

Estimate how much water you should drink each day based on your body weight and daily exercise, shown in litres, milliliters, and cups.

Convert between 12-hour AM/PM clock time and 24-hour military time format instantly.

Sum a list of hour:minute durations and optionally find the end time from a start clock time.

Add or subtract any number of days from a date to find the resulting date and weekday. Free date add/subtract days calculator.

Add or subtract years, months, weeks, days, hours, minutes and seconds from any date and time.

Calculate exact age in years, months and days between a birth date and any date.

See your exact age expressed in years, months, weeks, days, hours and minutes from any reference date.

Count the working days (Monday to Friday) between two dates, excluding weekends. Free business days and weekday counter.

Find the calendar date N working days after or before a start date, skipping weekends (and optional holidays).

Live countdown showing days, hours, minutes and seconds remaining until any future date and time.

Parse a 5-field cron expression, describe it in plain English, and compute the next several run times from a chosen start date.

Calculate the exact difference between two dates in years, months, days, weeks and total days. Free online date duration calculator.

Convert one date into many formats: ISO 8601, US, European, long form, ordinal and Unix epoch.

Find what day of the week any date falls on. Free day-of-week calculator showing the weekday, day of year, ISO week number and leap-year status.

Find which day of the year a date is (1-366) and how many days remain in the year.

Find how many days are in any given month and year, with leap-year February handled automatically.

Count the number of days from today until any future date, plus the number of weeks remaining. Free countdown to a date calculator.

Count down the days until your next birthday and see the age you will turn.

Convert decimal hours to hours:minutes:seconds and back again for payroll and time tracking.

Convert a Unix epoch timestamp to a readable date in UTC or any fixed time-zone offset, with full date-time breakdown.

Convert Excel/Sheets serial date numbers to calendar dates and back, including the 1900 and 1904 date systems.

Convert ISO 8601 durations like P1Y2M10DT2H30M to total seconds, minutes, hours and days, or build a duration string from components.

Convert between Gregorian dates and ISO 8601 week dates (YYYY-Www-D), including ISO week number and weekday.

Convert an ISO 8601 year and week number into the exact calendar dates of that week.

Convert between Gregorian calendar dates and the astronomical Julian Day Number (JDN) and Julian Date used in astronomy.

Check whether any year is a leap year using the Gregorian rule, see why, and list the next few leap years and the number of days in February.

Convert between 24-hour military time and 12-hour AM/PM clock time instantly.

Convert between Minguo (Republic of China) years used in Taiwan and Western Gregorian years — ROC year = Gregorian − 1911.

Calculate the exact number of minutes (and seconds and hours) between two dates and times.

Find the approximate moon phase, illumination percentage and lunar age for any date.

Convert between calendar dates and the ISO ordinal date format YYYY-DDD (year plus day-of-year number).

Solve for pace, speed, distance or time for running, cycling and walking, with unit conversion.

Determine the calendar quarter, fiscal quarter and fiscal year for any date with a custom fiscal start.

Convert dates to and from the RFC 2822 / email header format like 'Tue, 27 Jun 2026 14:30:00 +0000'.

Find which meteorological/astronomical season a date falls in, by hemisphere, with progress through it.

Find ideal bedtimes or wake times based on 90-minute sleep cycles and time to fall asleep.

Compute sunrise, sunset and day length for any location and date using the NOAA solar formula.

Convert a past date and time into a human-friendly 'N units ago' phrase with a full breakdown.

Calculate the duration between two clock times, with optional crossing of midnight.

Add daily clock-in/clock-out times with breaks to get total hours, overtime and gross pay.

Calculate the duration between two times in hours and minutes, including overnight spans. Free time difference calculator.

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.

Convert Unix epoch milliseconds to a human-readable date and time, and back, with second and millisecond precision.

Convert Unix timestamps (epoch seconds) to a human-readable UTC and local date, and convert any date back to a Unix timestamp.

Convert a UTC time to any local time zone offset and back using fixed UTC offsets from -12:00 to +14:00.

Find the ISO 8601 week number for any date, with the ISO week year and weekday. Free what-week-is-it calculator.

Count how many Mondays, Fridays or any weekday fall between two dates (inclusive).

Find the number of full weeks and leftover days between two dates, plus the decimal week count.

Calculate hours worked from clock-in and clock-out times minus breaks, in decimal hours and hours:minutes. Free timesheet hours calculator.

Calculate arc length, radius, included angle and area of a circular arch from span and rise. For doorways, bridges and architectural arches.

Work out the aspect ratio of any size and find a missing width or height that keeps proportions.

Calculate how much asphalt (hot-mix) you need by weight and volume from area length, width and thickness. Supports metric and imperial.

Check if your bag meets airline weight limits. Enter bag weight, the airline allowance and the per-kg excess fee to see total charges.

Find out how long you can safely stay in the sun without burning, based on UV index, your Fitzpatrick skin type and sunscreen SPF.

Split a shared bill including tax and tip evenly among any number of people.

Calculate board feet and total cost for lumber from thickness, width, length and quantity.

Convert BPM to note durations in milliseconds, find the Italian tempo marking, and get beat frequency in Hz for any music tempo.

Estimate how many bricks or blocks and how much mortar a wall needs from wall area and brick size, minus openings.

Calculate how much salt to add to water for any brine concentration — perfect for pickling vegetables, lacto-fermentation, and curing.

Convert butter between US sticks, cups, tablespoons, teaspoons, grams, ounces, and pounds in one click.

Find how many minutes of walking, running, cycling or swimming burns a given number of calories.

Calculate carpet area and linear metres needed from a fixed broadloom width, with waste for matching and offcuts.

Recommend the right ceiling fan blade span for a room based on its floor area, with a downrod height tip.

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.

Calculate the required CFM airflow for any room using its dimensions and target air changes per hour (ACH).

Convert octal chmod digits (e.g. 755) to symbolic file permissions (rwxr-xr-x) and see what each bit means.

Calculate the chord length, sagitta, arc length and circular segment area from a circle radius and central angle.

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.

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.

Add up what your daily coffee habit really costs per week, month and year.

Get the perfect coffee-to-water ratio in grams for any brew strength or number of cups.

Estimate the daily, monthly and yearly cost of driving to work including fuel, tolls and parking.

Estimate concrete for a slab from length, width and thickness in metric or imperial units. Get the volume in cubic yards and cubic metres, plus 40, 60 and 80 lb bag counts.

Find how much each serving of a meal costs from the total price and number of servings.

See the true cost per use of any purchase based on price and how often you use it.

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.

Estimate decking boards, joists and fasteners for a deck from its size, board width and joist spacing.

Estimate how many diapers your baby needs and the total cost over any period, from a few weeks to a full year.

Roll any number of dice with any number of sides (NdM) and see each die plus the total.

Calculate the sale price and how much you save with any percentage discount.

Calculate the volume and surface area of a torus (donut shape) from major radius R and minor radius r in any length unit.

Calculate print DPI from image pixels and size, or the pixels needed for a sharp print.

Calculate Defects Per Million Opportunities (DPMO), the Six Sigma sigma level, and process yield for quality analysis.

Calculate drywall sheets, screws, joint compound and tape for a room from wall and ceiling area.

Find the exact date of Easter Sunday for any year from 1583 to 9999 using the Meeus/Jones/Butcher Gregorian algorithm.

Calculate your effective DPI (eDPI) by multiplying mouse DPI × in-game sensitivity, and find your cm/360° rotation distance.

Calculate an appliance's energy use in kWh and its running cost from wattage, hours per day, days and your per-kWh electricity rate.

Calculate how much epoxy resin and hardener to mix for any casting or tabletop project — enter mold dimensions, mix ratio and a waste allowance.

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.

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.

Calculate fence posts, panels, rails and pickets for a run of fencing from total length and spacing.

Calculate the Exposure Value (EV) from your aperture, shutter speed and ISO — instantly see how your camera settings map to scene brightness.

Find out exactly what score you need on your final exam to reach your target grade, based on your current grade and the exam weight.

Convert a stacked woodpile into cords and face cords from length, width and height, and check value per cord.

Calculate flag height, area, diagonal and perimeter from the width and aspect ratio — useful for ordering fabric or making flags to correct proportions.

Calculate the exact nut-to-fret distance for any fret on a guitar, bass or other fretted instrument from the scale length.

Estimate the fuel cost of any trip from distance, vehicle efficiency and fuel price, plus litres needed and cost per kilometre.

Calculate gas cost for any trip from distance, MPG or L/100 km, and fuel price — plus fuel needed and CO₂ emissions.

Size a backup generator by summing the running and starting watts of the appliances you want to power.

Split a holiday or event gift budget fairly across everyone on your list.

Calculate your grade point average from each course's grade points and credit hours — a fast, accurate weighted GPA in seconds.

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.

Work out how much grass seed to buy for a new lawn or overseeding, based on area and the recommended seeding rate.

Work out how much gravel or aggregate you need from length, width and depth — get the volume in m³ and yd³, the weight in tonnes and US tons, and the cost.

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.

Add or remove GST at 5%, 12%, 18% or 28% and instantly see the net amount, the GST charged and the gross total.

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.

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.

Calculate GWAM (Gross Words A Minute) and NWAM (Net WPM) from keystrokes, test time and errors — with a speed-tier benchmark.

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.

Convert an IPv4 address to its 32-bit decimal integer (and hex/binary), or convert an integer back to dotted-quad form.

Calculate your Kill/Death (K/D) ratio, KDA ratio and win rate — for any FPS, battle royale or MOBA game.

Estimate how many laminate or hardwood floor packs and planks you need for a room, including a cutting-waste allowance.

Work out how much fertilizer to apply for a target nitrogen rate using the NPK percentage on the bag.

Calculate the LM317 output voltage from R1 and R2, or find R2 for a target output voltage — with minimum input voltage and power dissipation.

Pick random lottery numbers (e.g. 6 from 49) with no repeats, plus an optional bonus ball.

Calculate how many lumber boards you need for a deck, floor, or wall project, with a waste allowance and total cost estimate.

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.

Estimate thin-set mortar and tile grout for a tiling job from area, tile size and joint width.

Calculate how much cement, sand and water you need for a masonry mortar mix from area, joint depth and mix ratio.

Calculate miles per gallon (MPG) or L/100 km fuel economy, plus trip cost and cost per mile from distance and fuel used.

Find how many cubic yards or bags of mulch you need from bed length, width and depth, with bag-count and volume.

Work out how many litres of paint you need from your wall area, the paint's coverage per litre and the number of coats.

Calculate how many boxes fit on a standard pallet, how many layers stack within a height limit, and the total loaded weight.

Calculate the even or odd parity bit for any binary word — shows the complete data word with its parity bit appended.

Plan how much food, drink and ice to buy for a party based on guests and length.

Estimate password strength in bits of entropy and approximate crack time from its length and character set.

Generate a strong random password and measure its strength as entropy in bits.

Find how many pavers and how much bedding sand a patio or path needs from area and paver size.

Calculate the PERT expected task duration, standard deviation and confidence intervals from optimistic, most likely and pessimistic time estimates.

Calculate how many pizzas to order for any group size — choose appetite level, slices per pizza and an optional buffer for seconds.

Calculate pond volume in US gallons and litres for rectangular, oval or circular ponds, plus pump size and fish stocking capacity.

Calculate swimming pool volume in US gallons and litres, shock chlorine dose and filter pump size for rectangular, oval or circular pools.

Calculate a display's pixels-per-inch and dot pitch from its resolution and diagonal size.

Calculate how much fabric you need for a quilt: top, backing and binding yardage from quilt size, block size, seam allowance and fabric width.

Draw one or more random winners from a list of entries, with optional weighted tickets.

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.

Generate a random color and get its HEX, RGB and HSL codes instantly.

Generate one or many random integers within any range you choose — great for draws, picks, games, sampling and quick decisions.

Shuffle a list of names into balanced random teams of nearly equal size.

Estimate how long a text takes to read from its word count and your reading speed.

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.

Double, triple or halve any recipe instantly by scaling every ingredient to your desired number of servings.

Estimate roofing squares and shingle bundles from roof footprint and pitch, including waste for ridges and cuts.

Size an air conditioner or heater in BTU for a room from its area, sun exposure, ceiling height and occupants.

Convert RPM to angular velocity (rad/s), frequency (Hz), period, and peripheral speed — for motors, engines, wheels, and fans.

Calculate the sag (mid-span deflection) and cable length of a wire or cable between two supports using the parabolic and catenary formulas.

Calculate how much sand you need by volume (m³, yd³) and weight (tonnes, kg) from area length, width and depth. Supports metric and imperial.

Convert a screen's diagonal size and aspect ratio into its real width, height and area.

Estimate calories burned during sexual activity by body weight, duration and intensity, using MET values from Ainsworth's Compendium (2011).

Calculate how many squares of exterior siding you need from house dimensions, gables, openings and waste allowance. Supports metric and imperial.

Calculate how many sod rolls or pallets you need to cover a lawn, including a waste allowance for trimming.

Calculate the area of a rectangular room or space in square feet and square metres from its length and width, plus an optional total material cost.

Calculate stair risers, treads and stringer length from total rise, checking the 2R+T comfort rule.

Calculate stair riser height, tread going, stringer length and pitch angle from total rise and number of risers.

Calculate how many tonnes of decorative stone, pebbles or chippings you need by area and depth, with bag count and cost estimate.

Enter an IPv4 address and prefix (CIDR) to get the network address, broadcast, usable host range, host count and subnet mask.

Total up all your streaming and app subscriptions into one monthly and yearly figure.

Calculate sulfur (SO₂) emissions from burning coal, oil or diesel by entering the fuel mass and its sulfur content by weight.

Calculate the included taper angle, half-angle, taper per foot (or per 300 mm) and taper ratio from two diameters and a length.

Calculate pitch diameter, minor diameter, thread depth and lead angle for metric ISO and unified (UNC/UNF) screw threads.

Find how many tiles you need for a floor from the room area and tile size, with a waste allowance for cuts and breakages.

Work out the tip, total bill and amount per person — perfect for splitting a restaurant bill.

Estimate topsoil volume, weight and bag count for a garden bed or lawn from area and fill depth.

Estimate the full cost of owning a car or appliance including running costs and resale value.

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.

Calculate your typing speed in words per minute plus net WPM and accuracy from a timed test.

Compare two products by price per unit to find the cheaper buy — beat misleading package sizes and pick the best value every time.

Convert an availability SLA percentage (like 99.9%) into the allowed downtime per day, week, month and year.

Calculate the allowed downtime per year, month, week, and day for any uptime SLA percentage — from 90 % (one nine) to 99.9999 % (six nines).

Work out how many wallpaper rolls you need from room dimensions, roll size and pattern repeat, with trim and waste built in.

Convert any number of weeks to days, hours, minutes, seconds, months and years instantly. Fractional weeks are supported.

Find the ramp length and slope needed for a given rise and check it against the ADA 1:12 maximum.

Let chance decide: get a random Yes or No with adjustable odds and see the probability split.

Calculate classification accuracy, precision, recall, F1 score, specificity and NPV from a confusion matrix (TP, TN, FP, FN).

Run a one-way ANOVA F-test from group summary statistics (n, mean, SD) and get the F statistic, p-value, and effect size.

Update a prior into a posterior probability using sensitivity and false-positive rate via Bayes rule.

Find binomial probabilities P(X=k), at most or at least k successes in n trials, plus mean and variance.

Probability that at least two people in a group share a birthday, for any group size and number of days.

Odds of drawing favorable cards from a deck: exactly k, or at least one, in n draws without replacement.

Test whether observed counts match expected counts or proportions with a chi-square test.

Test association between two categorical variables from a contingency table.

Compute the coefficient of variation (CV = SD/mean) as a percentage from data or summary stats.

Probability of getting k heads in n coin flips (fair or biased), exactly, at least or at most.

Find P(A given B) from the joint probability and P(B), and check whether two events are independent.

Calculate a confidence interval for a mean using the z-distribution. Free online confidence interval calculator for 90%, 95% and 99% levels showing margin of error, lower and upper bounds.

Calculate the Pearson correlation coefficient (r) between two data sets to measure the strength and direction of their linear relationship. Free online correlation calculator with r² and slope.

Compute sample or population covariance between two equal-length variables x and y.

Calculate all nine deciles (D1–D9) for any data set. Deciles divide data into ten equal parts at the 10th, 20th, … 90th percentiles.

Compute mean, median, mode, range, variance and standard deviation for any data set.

Calculate the expected value, min, max, variance, and standard deviation for any dice expression (NdS + modifier).

Probability of rolling a target sum with any number and type of dice, exactly, at least or at most.

Apply the 68-95-99.7 rule to a normal dataset: get the one, two and three sigma intervals and percentages.

Compute expected value, variance and standard deviation from a discrete probability distribution table.