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Pick a calculator. Each one shows the answer as you type, with the worked steps underneath.

Percentage calculatorFind a percent of any number, such as 15% of 200.Open the calculator ›What percent is X of YTurn a part and a whole into a percent, such as 30 out of 200.Open the calculator ›X is Y% of what numberFind the whole when you know a part and its percent.Open the calculator ›Percent change calculatorPercent increase or decrease from an old value to a new value.Open the calculator ›Percent increase calculatorAdd a percent to a number, such as 200 plus 15%.Open the calculator ›Percent decrease calculatorTake a percent off a number, such as 200 minus 15%.Open the calculator ›Percentage difference calculatorCompare two values without choosing which is the base.Open the calculator ›Fraction to percentConvert a fraction such as 3/8 to a percent and a decimal.Open the calculator ›Grade percentage calculatorTurn points earned out of points possible into a percent.Open the calculator ›Discount calculatorSale price and savings from an original price and a percent off.Open the calculator ›Sales tax calculatorAdd sales tax at the rate you enter to any price.Open the calculator ›Tip calculatorTip, total and the amount each person pays.Open the calculator ›Markup and margin calculatorProfit, margin and markup from a cost and a selling price.Open the calculator ›Celsius to FahrenheitConvert °C to °F with the worked formula.Open the calculator ›Fahrenheit to CelsiusConvert °F to °C with the worked formula.Open the calculator ›Temperature converter (°C, °F, K)Convert between Celsius, Fahrenheit and Kelvin in one place.Open the calculator ›Commission calculatorCommission earned on sales, with optional base pay.Open the calculator ›Trapezoid area calculatorArea and median of a trapezoid from its parallel sides and height.Open the calculator ›Mean calculatorArithmetic mean (average) of a list of numbers.Open the calculator ›Divisibility calculatorCheck which of 2 to 12 divide a number, with the rules.Open the calculator ›Mulch calculatorMulch needed to cover a garden bed to a chosen depth.Open the calculator ›Cubic yard calculatorVolume in cubic yards from length, width and depth in any unit.Open the calculator ›Volts, amps and watts calculatorFind watts, amps or volts from the other two.Open the calculator ›Voltage drop calculatorVoltage drop over a wire run from AWG size, length and current.Open the calculator ›Cross product calculatorCross product, dot product, magnitude and angle of two 3D vectors.Open the calculator ›Prime factorization calculatorBreak a number into prime factors, and count its divisors.Open the calculator ›Factorial calculatorn factorial, exact for any n up to 170.Open the calculator ›Pythagorean theorem calculatorFind the hypotenuse or a missing leg of a right triangle.Open the calculator ›Percent error calculatorHow far a measured value is from the true value, as a percent.Open the calculator ›Age calculatorExact age in years, months and days, plus total days and the next birthday.Open the calculator ›Day of the week calculatorWhat weekday any date falls on, with day of year and ISO week.Open the calculator ›Remainder theorem calculatorFind the remainder of a polynomial divided by (x − r) without long division.Open the calculator ›Dot product calculatorDot product, magnitudes and angle between two vectors.Open the calculator ›Ellipse calculatorArea, perimeter, eccentricity and focal distance of an ellipse.Open the calculator ›Five number summary calculatorMinimum, quartiles, median, maximum, IQR and outliers.Open the calculator ›Relative error calculatorAbsolute, relative and percent error between a measured and a true value.Open the calculator ›pH calculatorConvert between pH, pOH, hydrogen ion and hydroxide concentration.Open the calculator ›Wind chill calculatorThe "feels like" temperature from air temperature and wind speed.Open the calculator ›RREF calculatorRow-reduce a matrix to reduced row echelon form with exact fractions and steps.Open the calculator ›

Percent calculators

Everyday calculators

Finance calculators

Health and fitness calculators

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    Home, school and electrical calculators

    Math calculators

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    Temperature converters

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    Method: standard arithmetic shown step by step; no outside data is used. Checked 2026-11-12.

    Written by Calculators Free Editorial Team · Data checked 2026-11-12
    About · How we verify this · Editorial policy · Corrections

    General information only. Results are plain arithmetic on the numbers you enter; check anything important (money, health, school work) against your own records or the official source.