Science-backed fitness math, in one place

BicepCalc brings together the calculators lifters actually use, each built on an established formula rather than guesswork. Estimate your one-rep max from a working set, set calorie and macro targets for a cut or bulk, check where your lifts fall against common strength standards, and track body composition over time.

Every tool runs entirely in your browser. Nothing you type is sent to a server, stored, or shared. Pick a calculator above to get started, or read the frequently asked questions to understand how each formula works and where its limits are.