Every number, answered with precision
Mortgages, body metrics, percentages and unit conversions — the everyday calculations that matter, worked out instantly and with the maths shown.
33
Calculators
4
Categories
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The library
Browse by category
Four categories, 33 calculators. Each one opens instantly and shows exactly how the answer was reached.
Financial Calculators
9 calculators
Mortgages, loans, savings and investments — see exactly where every pound, dollar or euro goes.
View all 9 finance calculatorsHealth Calculators
8 calculators
Body metrics, daily calories and key dates, built on the formulas clinicians actually use.
View all 8 health calculatorsMath Calculators
8 calculators
Arithmetic, algebra, statistics and probability — with the working shown, not just an answer.
View all 8 maths calculatorsConversion Calculators
8 calculators
Metric and imperial units converted exactly, from millimetres to miles and grams to stones.
View all 8 conversion calculatorsStart here
Most used calculators
The tools people reach for most often — from monthly mortgage payments to a quick BMI check.
Built to be checked, not just trusted
A calculator is only useful if you can see where the number came from. Every page shows the formula, a worked example and a breakdown you can follow with a pencil.
The maths, shown
Every result comes with the formula used and a line-by-line breakdown, so you can check it yourself.
Answers as you type
Results update the moment an input changes. No page reloads, no waiting, on phone or desktop.
Nothing leaves your browser
What you type is never stored or sent to a server. Refresh the page and it is gone.
Free, funded by ads
No paywalls and no subscriptions. Advertising keeps all 33 calculators open to everyone.
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