About CalcHub

CalcHub is a free calculator library built on one principle: a number you cannot check is a number you should not trust. Every one of our 170 calculators prints the exact formula it uses and a worked example with real numbers, so you can verify the method before you rely on the result.

How we keep results accurate

Each calculator's formula lives in a tested formula library. Automated tests feed known inputs with known correct outputs — the same checks used in school textbooks and official references (IRS brackets for the tax calculator, Mifflin-St Jeor for BMR, exact international definitions for unit conversions). A calculator is only published after its tests pass.

What the site is — and is not

Results are estimates for education and planning. They are not financial, medical, tax or legal advice. For decisions that matter, confirm the figure with a qualified professional — and if you ever find a result here that disagrees with a reliable source, tell us and we will fix it.

Privacy in one paragraph

Calculations run without an account and we do not store the numbers you enter into calculators. If you use the contact form, your message is stored so we can read and reply to it. Analytics and advertising cookies are used only with your consent. Full details are in the Privacy Policy.