All Calculators
Every calculator on this site, grouped by what it does. They all update as you type, show the formula with your own numbers in it, and expand to reveal the working line by line.
Percentages & money
Discounts, markups, unit prices and the percentage conversions people actually look up.
Percent Off CalculatorSale price, savings, stacked discounts and sales tax.Markup CalculatorSolve for cost, markup, price or profit — any two.Percent Error CalculatorAccepted vs measured, with absolute and signed error.Unit Price CalculatorCompare four sizes and find the real best value.Reverse Percentage CalculatorWork back to the original amount before a change.Percent to Decimal CalculatorAny percentage as a decimal, fraction and per mille.Decimal to Percent CalculatorAny decimal as a percentage, with the fraction too.Ratio to Percentage CalculatorA:B as a percentage, both ways of reading it.
Averages & statistics
Mean, median and weighted average, with every value plotted and every step shown.
Fractions
Convert between mixed numbers and improper fractions, and do arithmetic on them.
Arithmetic & number rules
Long multiplication and division, rounding, significant figures, order of operations and exact big-number maths.
Significant Figures CalculatorRound to N sig figs, or count the ones you have.Multiplication CalculatorProducts with the partial-product working shown.Rounding CalculatorEvery rounding place and rule, side by side.Division CalculatorLong division worked through digit by digit.Remainder CalculatorRemainder, quotient and modulo — negatives included.Big Number CalculatorExact arithmetic on numbers of any length.Absolute Value Calculator|x| for numbers and full expressions.Order of Operations CalculatorAny expression solved in the correct order.PEMDAS CalculatorPEMDAS, BODMAS and BIDMAS, one step at a time.
The basic calculator
The plain four-function keypad, with a tape.