How we calculate

Each calculator runs one documented formula. The formula, a worked example and the sources are shown on the same page, so you can check the result by hand.

Data and updates

Where a result depends on changing data such as tax rates, score tables or material weights, the page states the date it was last reviewed. We review that data on a schedule and when the source changes.

Testing

Every formula is covered by automated tests that check known answers before a page is published.

Corrections

Found a mistake? Email hello@xcalculator.cc with the inputs you used and the result you expected.