About CalcMate

CalcMate is a collection of 103 free online calculators that run entirely in your browser. No signup, no downloads, nothing to install.

What makes it different

Most calculator sites give you a form and a number. Every calculator here also shows the formula it uses, a worked example with real numbers, and a plain-English explanation of what each result means — so you can check the math and learn how it works.

Accuracy

Each calculator cites the standard or source behind its formula (WHO, CDC, IRS, textbook formulas, and so on) in the "Formula and calculation" section. Results are estimates where the underlying data changes (tax rates, CPI, exchange rates), and the page says so together with the date the data is from.

Privacy

Everything you type stays in your browser — calculations are done on your device and nothing is sent to a server. See the privacy page for details.

Found a bug or a number that looks wrong? Tell us — corrections are welcome.