All calculators
Every tool on the site, grouped by what you are trying to work out. All of them run in your browser and answer as you type.
Percentages & shopping
8 tools →Everyday maths at the till: discounts, tips, tax and margins.
Percentage calculatorWhat is X% of Y, and X is what percent of Y.
Percentage increase & decreaseHow much something went up or down, in percent.
Discount & sale priceSale price and how much you actually save.
Tip calculatorTip, total, and what each person owes.
Split the billDivide a bill evenly, with the rounding handled.
VAT & sales taxAdd tax on top, or strip it out of a gross price.
Margin & markupProfit margin, markup, and the price you should charge.
Unit price comparisonWhich pack size is actually cheaper.
Loans & mortgages
5 tools →Work out what a loan really costs before you sign anything.
Loan paymentMonthly payment, total interest, total cost.
Mortgage calculatorHouse price, deposit and rate to a monthly figure.
Amortization schedulePayment-by-payment breakdown, with overpayments.
Car loan calculatorPrice, trade-in and deposit to a monthly payment.
Interest-only paymentThe monthly cost when nothing is repaid.
Saving & investing
4 tools →See how money grows — and what inflation quietly takes back.
Income & budget
3 tools →Turn pay rates into real numbers and split them sensibly.
Converters
11 tools →Units, measures and currencies, converted both ways in one tap.
Currency converterLive daily rates between the world's main currencies.
Length converterMetres, feet, inches, miles — converted both ways.
Weight converterKilograms, pounds, stone, ounces and grams.
Temperature converterCelsius, Fahrenheit and Kelvin at a glance.
Volume converterLitres, millilitres, gallons, cups and pints.
Area converterSquare metres, square feet, acres and hectares.
Speed converterkm/h, mph, m/s and knots.
Data storage converterMB, GB, TB — and the binary units behind them.
Time unit converterSeconds, minutes, hours, days, weeks and years.
Fuel consumption converterL/100 km, MPG and km per litre.
Cooking measurement converterCups to grams for the ingredients you actually bake with.
Maths & numbers
5 tools →Fractions, averages, geometry and a fair coin when you need one.
Coin flipHeads or tails, instantly — flip one coin or a hundred.
Random number generatorPick numbers in any range, with or without repeats.
Fraction calculatorAdd, subtract, multiply and simplify fractions.
Average calculatorMean, median, mode, range and standard deviation.
Geometry calculatorArea, perimeter and volume for everyday shapes.
Dates & time
4 tools →Ages, deadlines and the gap between any two dates.