Fitness and Health Calculators

Body composition, energy needs and training targets.

34 free tools

Most used

All 34 health calculators

About these health calculators

Health calculators translate a couple of measurements into something you can act on: a calorie target, a training zone, a body composition estimate. They apply population-level equations to an individual, which makes them genuinely useful for tracking direction over time and unreliable as a verdict on any single day.

Where several accepted formulas exist — BMR, body fat, ideal weight — the tools show all of them rather than picking one silently, because the spread between them tells you how much confidence the number deserves. Each page explains what the measure misses as well as what it captures.