All calculators & converters

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

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

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

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.

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

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

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.

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.

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

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

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

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.

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

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.

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.

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.

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

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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.

Add VAT to a net price or remove VAT from a gross price, showing the net amount, the VAT and the gross total for any VAT rate.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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.

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

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

Find the percentile value of any data set using linear interpolation. Free online percentile calculator that ranks your numbers and returns the value at any chosen percentile.

Calculate permutations (nPr) and combinations (nCr) for any n and r. Free online permutation and combination calculator using factorials, with instant results.

Calculate the probability of two independent events: P(A and B), P(A or B) and the complement P(not A). Free online probability calculator for single and combined events.

Calculate population and sample standard deviation, variance and mean of any data set instantly. Free online standard deviation calculator with step-by-step results.

Calculate a weighted average (weighted mean) from value and weight pairs. Free online weighted average calculator for grades, GPAs, prices and survey data.

Calculate the z-score (standard score) of a value from its mean and standard deviation. Free online z-score calculator showing how many standard deviations a point is from the mean.

Calculate the area, circumference and diameter of a circle from its radius.

Calculate the volume, slant height and surface area of a right circular cone from its radius and height.

Calculate the volume, surface area and space diagonal of a cube from a single edge length using exact formulas.

Calculate the volume and surface area of a cylinder from its radius and height using exact formulas with π.

Calculate the area and approximate perimeter of an ellipse from its semi-major and semi-minor axes using Ramanujan’s formula.

Calculate the area and perimeter of a parallelogram from its base, perpendicular height and side length.

Calculate the volume, slant height and surface area of a square pyramid from its base edge and height.

Calculate the area, perimeter and diagonal of a rectangle instantly from its length and width with exact formulas.

Calculate the area, side length and perimeter of a rhombus from its two diagonals using exact geometric formulas.

Calculate the volume, surface area and diameter of a sphere from its radius using exact formulas with π.

Calculate the area, perimeter and diagonal of a square from a single side length using exact geometric formulas.

Calculate the area of a trapezoid from its two parallel sides and the perpendicular height between them.

Find the area of a triangle from its base and height, or from three side lengths using Heron’s formula, plus the perimeter.

Calculate acceleration from the change in velocity over time using a = (vf − vi) / t. Get results in m/s² and in multiples of g.

Calculate density from mass and volume using density = mass / volume. Get instant results in kg/m³ and g/cm³ for solids, liquids and gases.

Calculate force from mass and acceleration using Newton's second law, F = m × a. Get instant results in newtons, kilonewtons and kilogram-force.

Calculate the kinetic energy of a moving object from its mass and velocity using KE = ½mv². Results in joules, kilojoules and kilocalories.

Calculate voltage, current, resistance and power using Ohm's law — enter any two values.

Calculate gravitational potential energy from mass and height using PE = m·g·h with g = 9.80665 m/s². Results in joules and kilojoules.

Calculate power as work divided by time using P = W / t. Get instant results in watts, kilowatts and mechanical horsepower.

Calculate pressure from force and area using P = F / A. Get instant results in pascals, kilopascals, psi and bar.

Calculate average velocity from distance and time using v = d / t. Get instant results in metres per second, kilometres per hour and miles per hour.

Calculate wavelength from wave speed and frequency using λ = v / f. Works for light, sound and radio waves, with results in metres, centimetres and nanometres.

Calculate mechanical work from force, distance and the angle between them using W = F·d·cos(θ). Results in joules, kilojoules and kilocalories.