Free Online Calculators

Fast, accurate calculators for money, health, math and everyday life — no sign-up, works on any device.

Popular calculators

Mortgage Calculator Income Tax Calculator BMI Calculator Percentage Calculator Loan Calculator Tip Calculator Age Calculator Compound Interest Calculator

Finance

Mortgages, loans, savings and investment math.

Mortgage Calculator Estimate your monthly home loan payment — principal, interest, taxes and insurance. Loan Calculator Work out the monthly payment and total interest on any personal, auto or student loan. Compound Interest Calculator See how savings and investments grow with compound interest and regular contributions. Simple Interest Calculator Calculate simple interest on a principal over time — no compounding. Credit Card Payoff Calculator See how long it takes to clear a credit card balance and the interest it costs. Fuel Cost Calculator Work out the fuel cost of a trip from distance, efficiency and fuel price. Auto Loan Calculator Estimate the monthly payment on a car loan, including tax and trade-in. Retirement Calculator Project your retirement savings from your contributions and expected return. Savings Goal Calculator Find out how long it takes to reach a savings goal with regular deposits. Profit Margin Calculator Calculate profit margin, markup and profit from cost and selling price. Future Value Calculator See what a sum of money will be worth in the future with interest and contributions. Present Value Calculator Find what a future amount of money is worth in today’s money. ROI Calculator Calculate return on investment as a percentage, plus profit and annualised return. Annuity Payout Calculator Work out the regular income a lump sum can pay out over a set number of years. APR to APY Calculator Convert a nominal APR into the effective annual yield (APY) for any compounding. CD Calculator Calculate the maturity value and interest on a certificate of deposit. Inflation Calculator See how inflation changes the buying power and future cost of money over time. Home Affordability Calculator Estimate how expensive a house you can afford from your income, debts and down payment. Rent Affordability Calculator Find out how much rent you can afford based on your income. Down Payment Calculator Work out the down payment amount and loan needed for a given home price. Refinance Calculator Compare your current mortgage to a new rate and find the break-even point. Debt-to-Income Ratio Calculator Calculate your DTI ratio — the share of income going to debt payments. Boat Loan Calculator Estimate the monthly payment and interest on a boat loan. Student Loan Calculator Estimate the monthly payment and total interest on a student loan. Personal Loan Calculator Calculate the monthly payment, interest and net amount received on a personal loan. Car Lease Calculator Estimate a monthly car lease payment from price, residual value and money factor. Net Worth Calculator Add up your assets and subtract your debts to find your net worth. Break-Even Point Calculator Find how many units you must sell to cover your costs. SIP Calculator Project the maturity value of a monthly systematic investment plan (SIP). EMI Calculator Calculate the equated monthly instalment (EMI) on any loan.

Tax & Salary

Income tax, take-home pay, VAT and sales tax by country.

Income Tax Calculator Estimate the income tax on your salary and see your take-home pay. Sales Tax & VAT Calculator Add or remove sales tax, VAT or GST from any price.

Health & Fitness

BMI, calories, body metrics and fitness.

BMI Calculator Calculate your Body Mass Index and see which category it falls in. Calorie (TDEE) Calculator Estimate the daily calories you burn and how much to eat to lose or gain weight. Body Fat Calculator Estimate your body fat percentage with the U.S. Navy tape method. Ideal Weight Calculator Find a healthy target weight range for your height and sex. Water Intake Calculator Estimate how much water to drink each day for your weight and activity. BMR Calculator Calculate your Basal Metabolic Rate — the calories you burn at rest. Running Pace Calculator Work out your running pace and speed from distance and time. Macro Calculator Split a daily calorie target into protein, carbohydrate and fat grams. Calorie Deficit Calculator Find the daily calories to hit a target weekly weight-loss rate. Protein Intake Calculator Estimate your daily protein target in grams from body weight and goal. One Rep Max Calculator Estimate your 1RM from a weight and reps, with a percentage training table. Maximum Heart Rate Calculator Estimate your maximum heart rate from your age. Heart Rate Zone Calculator Calculate your five training heart-rate zones from age and resting heart rate. Blood Alcohol (BAC) Calculator Estimate blood alcohol concentration from drinks, body weight and time. Pregnancy Due Date Calculator Estimate your due date and how many weeks pregnant you are from your last period. Ovulation & Fertility Calculator Estimate your ovulation day and fertile window from your last period. Waist-to-Hip Ratio Calculator Calculate your waist-to-hip ratio and see the associated health risk band. Waist-to-Height Ratio Calculator Calculate your waist-to-height ratio — a simple central-obesity screen. Lean Body Mass Calculator Estimate your lean body mass and fat mass using the Boer formula. Army Body Fat Calculator Estimate body fat with the U.S. Army (AR 600-9) tape method and check the standard. Calories Burned Calculator Estimate calories burned in an activity from its MET value, your weight and time. Steps to Miles Calculator Convert step count into miles and kilometres using your height and pace. Sleep Cycle Calculator Find the best bedtimes or wake times based on 90-minute sleep cycles. Body Surface Area Calculator Calculate body surface area (BSA) with the Mosteller and Du Bois formulas.

Math

Percentages, fractions, algebra, geometry.

Percentage Calculator Work out what X% of a number is, and what one number is as a percent of another. Average (Mean) Calculator Find the mean, median, sum and count of a list of numbers. Percentage Change Calculator Calculate the percentage increase or decrease between two numbers. Ratio Calculator Simplify a ratio and convert it to a decimal. Fraction Calculator Add, subtract, multiply or divide two fractions and simplify the result. Fraction to Percent Calculator Convert any fraction into a percentage and a decimal. Mixed Number to Improper Fraction Calculator Convert a mixed number to an improper fraction, decimal and simplest form. Exponent (Power) Calculator Raise any base to any power, including negative and fractional exponents. Nth Root Calculator Find the square, cube or any nth root of a number. Square Root Calculator Find the square root of a number and its simplified radical form. Logarithm Calculator Calculate the logarithm of a number in any base, plus the natural log. GCD & LCM Calculator Find the greatest common divisor and least common multiple of a list of numbers. Prime Factorization Calculator Break a number down into its prime factors. Factorial Calculator Compute the factorial n! of a whole number, exactly — even very large values. Permutation Calculator (nPr) Count the ordered arrangements of r items chosen from n. Combination Calculator (nCr) Count the ways to choose r items from n when order does not matter. Quadratic Formula Calculator Solve any quadratic equation ax² + bx + c = 0, including complex roots. Slope Calculator Find the slope, y-intercept and equation of the line through two points. Distance Between Two Points Calculator Find the straight-line distance between two points on a plane. Midpoint Calculator Find the point exactly halfway between two coordinates. Pythagorean Theorem Calculator Solve a right triangle: find the hypotenuse or a missing leg. Area Calculator Calculate the area of a rectangle, triangle, circle, trapezoid or parallelogram. Circle Calculator Find a circle’s area, circumference and diameter from any one measurement. Volume Calculator Calculate the volume of a box, cylinder, sphere or cone. Scientific Notation Converter Convert any number to and from scientific notation. Rounding Calculator Round a number to any number of decimal places, up or down.

Statistics

Averages, probability, tests and distributions.

Mean, Median, Mode Calculator Find the mean, median, mode and range of a list of numbers. Standard Deviation Calculator Calculate sample or population standard deviation, variance and mean. Variance Calculator Compute the sample or population variance of a data set. Mean Absolute Deviation Calculator Find the mean absolute deviation (MAD) of a data set. Coefficient of Variation Calculator Measure relative variability as the ratio of standard deviation to mean. Percentile Calculator Find the value at any percentile and the quartiles of a data set. Z-Score Calculator Convert a raw value to a z-score and find its percentile. P-Value Calculator (from Z) Convert a z-score to a one- or two-tailed p-value. Confidence Interval Calculator Build a confidence interval for a mean from the sample mean, SD and size. Margin of Error Calculator Find the margin of error of a survey proportion. Sample Size Calculator Find the survey sample size for a target margin of error. Probability Calculator Combine two independent event probabilities: and, or, neither. Binomial Probability Calculator Find the probability of k successes in n independent trials. Normal Distribution Calculator Find the probability density and cumulative probability for a normal value. Correlation Coefficient Calculator Compute Pearson’s r between two lists of numbers.

Unit Converters

Length, weight, temperature, data and more.

Length Converter Convert length and distance between metric and imperial units. Weight & Mass Converter Convert weight and mass between grams, kilograms, pounds, ounces and more. Temperature Converter Convert temperatures between Celsius, Fahrenheit and Kelvin. Speed Converter Convert speed between km/h, mph, m/s, ft/s and knots. Area Converter Convert area between square meters, square feet, acres, hectares and more. Volume Converter Convert volume between liters, gallons, cups, milliliters and more. Time Converter Convert time between seconds, minutes, hours, days, weeks and years. Data Storage Converter Convert digital storage between bits, bytes, KB, MB, GB, TB and binary units. Energy Converter Convert energy between joules, calories, kWh, BTU and more. Pressure Converter Convert pressure between pascals, bar, psi, atm and mmHg. Power Converter Convert power between watts, kilowatts, horsepower and BTU/hour. Angle Converter Convert angles between degrees, radians, gradians and turns. Fuel Economy Converter Convert fuel economy between MPG, L/100km and km/L. Frequency Converter Convert frequency between Hz, kHz, MHz, GHz, RPM and rad/s. Number Base Converter Convert numbers between binary, octal, decimal and hexadecimal. Roman Numeral Converter Convert whole numbers to Roman numerals and back. Cooking Measurement Converter Convert recipe amounts between cups, tablespoons, milliliters, grams and ounces.

Science & Engineering

Physics, electronics and chemistry tools.

Ohm's Law Calculator Solve for voltage, current or resistance and get the power — pick what to find. Voltage Drop Calculator Estimate the voltage lost along a wire run from length, current and conductor size. Resistor Color Code Calculator Decode a 4-band resistor colour code into resistance and tolerance. Capacitor Charge Calculator Find charge, energy, time constant and the charging voltage of an RC circuit. Electrical Power Calculator Calculate power in watts from voltage and current, with kilowatts and horsepower. Force Calculator (F = ma) Compute force from mass and acceleration using Newton's second law. Kinetic Energy Calculator Find the kinetic energy and momentum of a moving object. Potential Energy Calculator Calculate gravitational potential energy from mass, height and gravity. Density Calculator Solve for density, mass or volume — density is mass divided by volume. Molarity Calculator Find the molar concentration of a solution from mass, molar mass and volume. Ideal Gas Law Calculator Solve PV = nRT for pressure, volume, moles or temperature. Wavelength & Frequency Calculator Convert between wavelength and frequency and get the photon energy. pH Calculator Convert between hydrogen-ion concentration and pH, with pOH and [OH⁻]. Torque Calculator Calculate torque from force, lever length and the angle of application. Gear Ratio Calculator Work out gear ratio, output speed and torque multiplication from tooth counts. Projectile Motion Calculator Find the range, maximum height and flight time of a launched projectile. Subnet Calculator (IPv4 CIDR) Get the network, broadcast, mask and host range for an IPv4 address and CIDR prefix. Binary / Hex / Decimal Converter Convert a number between binary, octal, decimal and hexadecimal.

Date & Time

Age, date differences, durations, timers.

Age Calculator Find your exact age in years, months and days, and the countdown to your next birthday. Date Difference Calculator Count the days, weeks and months between two dates. Countdown Calculator Count down the days, hours and minutes to any date and time. Add or Subtract Days Calculator Add or subtract days, weeks, months or years from any date. Business Days Calculator Count the working days (weekdays) between two dates. Workdays From Date Calculator Find the date that is N business days before or after a start date. Days Until Date Calculator Count how many days remain until a future date. How Many Days Since Calculator Count how many days have passed since a date in the past. Week Number Calculator Find the ISO week number and day of the year for any date. Time Duration Calculator Find the length of time between two clock times. Hours Calculator Calculate hours worked between two times, with breaks and overtime. Time Card Calculator Turn a work shift and break into paid hours and pay. Unix Timestamp Converter Convert between a Unix epoch timestamp and a human date and time. Sleep Cycle Calculator Find the best times to go to sleep or wake up in whole sleep cycles.

Everyday

Tips, grades, fuel and day-to-day math.

Tip Calculator Calculate the tip and split the bill between any number of people. Discount Calculator Find the sale price and how much you save from any percentage discount. Salary to Hourly Calculator Convert a wage between hourly, daily, weekly, monthly and yearly. Final Grade Calculator Find the score you need on your final exam to hit a target grade. GPA Calculator Work out your grade point average from your course grades and credit hours. Grade Calculator Combine your assignment scores and their weights into an overall course grade. Test Score Calculator Turn the number of correct answers into a percentage score and letter grade. Letter Grade Calculator Convert a percentage score into a letter grade and GPA point value. Aspect Ratio Calculator Resize width and height while keeping the same aspect ratio. Unit Price Calculator Compare two package sizes to see which is the better value per unit. Sales Commission Calculator Work out commission earnings from a sale amount and commission rate. Random Number Generator Generate one or more random numbers within a range you choose. Dice Roller Roll any number of dice with any number of sides and get the total. Coin Flip Flip one or many coins and count the heads and tails. Recipe Scaler Scale a recipe ingredient up or down for a different number of servings. Paint Calculator Estimate how much paint you need to cover the walls of a room. Tile Calculator Find how many tiles you need for a floor or wall, including waste. Mulch & Soil Calculator Calculate the volume of mulch, soil or compost needed to cover an area. Concrete Calculator Work out the concrete volume and number of bags for a slab or footing.

Graphing & Advanced

Scientific, graphing, geometry and 3D calculators.

Scientific Calculator A full scientific calculator with trig, logs, powers, roots and constants — free and online. Graphing Calculator Plot functions on an interactive graph — free online graphing calculator, no sign-up. 3D Graphing Calculator Plot a surface z = f(x, y) in interactive 3D — rotate and zoom, free online. Matrix Calculator Add, multiply, transpose, and find the determinant and inverse of a matrix online. Equation Solver Solve linear, quadratic and systems of equations step by step, free online. Triangle Calculator Solve any triangle from sides and angles — area, perimeter and the missing values.