Calculators
Free calculators for percentages, fractions, finance, statistics, and everyday math, each with the formula and steps.
Age Calculator Calculate your exact age in years, months, and days from your date of birth, using today's date. Angle Converter Convert angles between degrees, radians, gradians, and turns. APY Calculator Find the annual percentage yield (APY) from a nominal rate and compounding frequency. Shows the formula and yearly earnings. Area Converter Convert area between square meters, square feet, square kilometers, acres, and hectares. Aspect Ratio Calculator Find the simplified aspect ratio of a width and height, like 1920 x 1080 = 16:9. Average Calculator Find the average (mean) of a list of numbers, or a weighted average where some count more. Shows the steps. Average Percentage Calculator Find the average of several percentages, or a weighted average where some count more. Shows the steps. BMI Calculator Calculate your Body Mass Index from height and weight, in metric or imperial units, and see which BMI category it falls in. CAGR Calculator Calculate the compound annual growth rate (CAGR) from a start value, end value, and number of years. Circle Calculator Find a circle's radius, diameter, circumference, and area from any one of them. Shows the formulas. Combination and Permutation Calculator Calculate combinations (nCr) and permutations (nPr) for choosing r items from n. Shows the formula and steps. Compound Interest Calculator Estimate compound interest and final amount with different compounding frequencies. Cube Root Calculator Find the cube root of a number, including negatives, with perfect-cube detection and the steps. Data Storage Converter Convert digital storage between bits, bytes, kilobytes, megabytes, gigabytes, and terabytes. Date Calculator Add or subtract days from a date to find the resulting date and weekday. Days Between Dates Calculator Count the number of days between two dates, shown as days and as weeks plus days. Decimal to Fraction Calculator Convert a decimal to a fraction in simplest form, with the mixed number and the steps. Depreciation Calculator Work out how much an asset loses in value each year. Straight line, declining balance, and double declining balance methods, with a year-by-year schedule and editable presets for a car, phone, laptop, and more. Discount Calculator Find the sale price and how much you save, add sales tax, or stack two discounts, all from the original price and percent off. Distance and Midpoint Calculator Find the distance between two points and their midpoint, with the formulas and steps. EMI Calculator Estimate an equated monthly installment using principal, annual interest rate, and loan tenure in months. Energy Converter Convert energy between joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, and BTU. Equivalent Fractions Calculator Generate equivalent fractions by multiplying the numerator and denominator by the same number. Exponent Calculator Raise any number to any power, including negative and fractional exponents. Shows what the power means. Factorial Calculator Calculate the factorial of a whole number (n!), with exact results and the steps. Fibonacci Retracement Calculator Enter a swing high and low to get the Fibonacci retracement levels (23.6%, 38.2%, 50%, 61.8%, 78.6%) and extension targets (127.2%, 161.8%, 200% and more). Fraction Calculator Add, subtract, multiply, and divide fractions with simplified answers. Fraction to Decimal Calculator Convert a fraction to a decimal and a percentage by dividing the numerator by the denominator. Fraction to Percent Calculator Convert a fraction to a percent by dividing and multiplying by 100. Shows the steps. Frequency Converter Convert frequency between hertz, kilohertz, megahertz, and gigahertz. Fuel Economy Converter Convert fuel economy between miles per gallon, liters per 100 km, and kilometers per liter. GCF and LCM Calculator Find the greatest common factor (GCF) and least common multiple (LCM) of two or more whole numbers. GPA Calculator Calculate your GPA on the 4.0 scale from course grades and credit hours. Add as many courses as you need. Grade Calculator Turn a test score into a percentage and letter grade, or find the marks needed for a target. Shows the steps. Interactive Wave Generator A visual sine wave playground: a spinning circle draws the wave, add waves to watch them combine, see them as a 3D helix, and turn on sound to hear them. Investment Payback Calculator Find out when an investment pays back: enter the capital, your average monthly income and cost, and see the payback period, a month-by-month table, and a chart - with or without the interest you give up. Investment Plan Comparison Calculator Compare investment plans. Same starting amount and time, different returns, to see which ends up ahead. Length Converter Convert length between millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles. Loan Calculator Estimate a monthly loan payment, total paid, and total interest using loan amount, rate, and term. Logarithm Calculator Calculate the logarithm of a number in any base using the change-of-base formula. Shows the steps. Long Division Calculator Divide whole numbers to get the quotient and remainder, with the long-division steps shown. Mean, Median, Mode Calculator Find the mean, median, mode, and range of a list of numbers, with the steps shown. Mixed Number Calculator Convert an improper fraction to a mixed number, or a mixed number to an improper fraction. Shows the steps. Modulo Calculator Find a mod b, the remainder after dividing a by b. Shows the quotient and the steps. Number Base Converter Convert a number between binary, octal, decimal, and hexadecimal. Shows all four at once. Number to Words Converter Spell out any number in words, including decimals and negatives. Useful for writing checks, forms, and legal documents. Percent Error Calculator Find the percent error between a measured value and the true value. Shows the formula and steps. Percent to Fraction Calculator Convert a percent to a fraction in simplest form, with the mixed number and the steps. Percentage Calculator Calculate percentages, find what percent one number is of another, or work backward from a percentage. Percentage Decrease Calculator Find the percentage decrease from an original value to a new smaller value. Percentage Increase Calculator Find the percentage increase from an original value to a new larger value. Power Converter Convert power between watts, kilowatts, megawatts, and horsepower. Pressure Converter Convert pressure between pascals, kilopascals, bar, atmospheres, psi, and mmHg. Prime Factorization Calculator Break a whole number into its prime factors, shown with exponents and expanded. Shows the steps. Probability Calculator Find the probability of a single event, combine two independent events, or repeat one event over multiple tries. Shows the chance as a percentage, fraction, decimal, and odds. Profit Margin Calculator Find profit, profit margin, and markup from a cost and selling price. Shows the formulas and steps. Pythagorean Theorem Calculator Find the hypotenuse or a missing leg of a right triangle using the Pythagorean theorem. Shows the steps. Quadratic Equation Calculator Solve ax² + bx + c = 0 with the quadratic formula. Shows the discriminant and real or complex roots. Random Number Generator Generate random numbers in any range, roll dice, or flip a coin. Choose how many and whether numbers can repeat. Ratio Calculator Simplify a ratio to its lowest terms, or solve a proportion a : b = c : ?. Shows the steps. Rectangle Calculator Find the area, perimeter, and diagonal of a rectangle from its length and width. Shows the formulas. ROI Calculator Calculate return on investment (ROI) and net gain from an initial cost and final value. Shows the steps. Roman Numeral Converter Convert numbers to Roman numerals and Roman numerals to numbers, from 1 to 3999. Shows how each numeral is built. Rounding Calculator Round a number to the nearest whole number, tenth, hundredth, ten, hundred, or thousand. Shows the result. Salary Calculator Convert pay between hourly, daily, weekly, monthly, and yearly. Set your own hours and weeks worked. Currency-agnostic. Sales Tax Calculator Add sales tax to a price or remove it from a total. Shows the tax amount and the steps. Savings Goal Calculator Find how much to save each month to reach a goal, like a million, given your timeline and expected return. Scientific Notation Calculator Convert a number to scientific notation, or scientific notation back to a standard number. Shows the steps. Significant Figures Calculator Round a number to N significant figures, or count the significant figures in a number. Simple Interest Calculator Calculate simple interest and total amount using principal, rate, and time. Simplifying Fractions Calculator Reduce a fraction to simplest form by dividing by the greatest common factor. Slope Calculator Find the slope of a line through two points, plus the line equation. Shows rise over run and the steps. Speed Converter Convert speed between km/h, mph, meters per second, feet per second, and knots. Square Root Calculator Find the square root of a number as a decimal, plus the simplified radical form for whole numbers. Shows the steps. Square Root, Step by Step See how to find a square root by hand, revealed step by step. Choose the regular long-division method or a fast approximation, and play the working through. Standard Deviation Calculator Find the standard deviation, variance, and mean of a data set, for a population or a sample. Shows the steps. Surface Area Calculator Find the surface area of a box, cube, sphere, cylinder, or cone. Shows the formula and the steps. Take Profit & Stop Loss Calculator Work out take profit and stop loss prices from a % , basis points, or points offset, and see the reward-to-risk ratio. Add named levels and an optional position size. Temperature Converter Convert temperatures between Celsius, Fahrenheit, and Kelvin. Shows all three at once with the formulas. Time Card Calculator Add up work hours from punch-in and punch-out times, minus lunch and breaks, for a weekly or biweekly timesheet. Total hours, per-week subtotals, and optional pay. Handles overnight shifts. Time Converter Convert time between seconds, minutes, hours, days, and weeks. Time Duration Calculator Find the duration between two clock times, in hours and minutes. Handles overnight spans. Tip Calculator Work out the tip and total for any bill, and split it between people. Shows the steps. Trading Expectancy Calculator Work out a trading strategy's expectancy: enter your win rate, average win, and average loss to see the average result per trade, in R-multiples, plus the break-even win rate. Trading Strategy Monte Carlo Simulator Test a trading strategy with Monte Carlo: enter a win rate and reward:risk, and see the range of outcomes over thousands of runs - profit odds, risk of ruin, drawdown, and equity curves. Triangle Area Calculator Find the area of a triangle from its base and height, or from its three sides with Heron's formula. Trigonometry Calculator Find the sine, cosine, and tangent of an angle in degrees or radians. Unit Price Calculator Compare two items by price per unit to see which is the better value. Shows the steps. Volume Calculator Find the volume of a box, cube, sphere, cylinder, or cone. Shows the formula and the steps. Volume Converter Convert liquid volume between milliliters, liters, cubic meters, US cups, pints, quarts, gallons, and fluid ounces. Weight Converter Convert weight between milligrams, grams, kilograms, ounces, pounds, stone, and metric tons. Z-Score Calculator Find the z-score (standard score) of a value from the mean and standard deviation.