Calculators that give you the number, then explain it

Every tool shows the formula it used and follows up with a plain guide to what the figure means. Nothing you type leaves your browser.

Asked most often

Work out a date, an age, or the hours between two times.

Payments, interest, payoff dates and what a loan really costs.

Materials, quantities and quotes for work around the house.

Body composition, training numbers and cycle dates.

Percentages, fractions and the arithmetic behind them.

Course grades, exam scores and what you still need.

Convert between measurement systems without guessing.

Current, power and what leaving something plugged in costs.

Fuel economy, running costs and the price of a journey.

Every tool states the maths it used, so you can check it rather than trust it.

The calculators run in your browser. Nothing you enter is sent to us, stored or logged.

Each page explains what the figure means, where it goes wrong, and when not to rely on it.