About CalcVitals

CalcVitals is a small, independent collection of health calculators, built and maintained by the CalcVitals team. We make the kind of page we could not find when we needed one: the answer, the formula behind it, and a worked example — all on the same page, free, with no account and no app to install.

Every tool states the published method it uses — Mifflin-St Jeor for metabolic rate, the US Navy tape method for body fat, Naegele's rule for due dates, Riegel's formula for race prediction — and prints an educational disclaimer, because a calculator is a starting point for a conversation with a professional, not a replacement for one.

Your inputs are processed entirely in your browser. We do not receive, store, or sell the figures you enter — there is nothing to store them in. The site is supported by advertising, which is also why it stays free.

Corrections are welcome. If a formula, a constant, or an explanation looks wrong, tell us at [email protected] and we will check it against the source and fix it in the open.