How we calculate

Sources

Every tax or legal number comes from an official source (a tax authority, a government service or the law itself), opened on the day we use it. We record the number, the link and the date. If we cannot open the official source, the number does not ship. A blog or a calculator site is never enough.

Country and year

Each tool and article names its country (for example “United States, federal taxes only”) and its tax year, near the top and next to the result. One country’s rule is never presented as universal.

Estimate or exact

A tool that models only part of a tax law is an estimate and says so. A tool that is pure arithmetic, such as invoice totals, is exact for the numbers entered.

What we leave out

Each tax tool lists, on the page, what it does not model, such as credits, local taxes and special cases.

Yearly updates

Tax figures change every year. We re-check them when new figures are published, and a tool never keeps last year’s numbers without saying so.

General information, not tax, legal or accounting advice.