This free body fat calculator estimates your total body fat percentage using the U.S. Navy body fat formula — a method trusted by fitness professionals, the Army body fat calculator, and USMC body fat calculator. It works for both men and women and provides extra results like lean body mass, fat mass, and an estimated organ/tissue breakdown.
Tracking body fat tells you more about your health than weight alone. Two people can weigh the same but have completely different body compositions. A fat percentage calculator helps you understand if your weight gain or loss is muscle, fat, or water.
The lean body fat calculator below shows your lean mass — the combined weight of muscles, bones, organs, and water — versus fat mass. Healthy ranges differ by gender, age, and lifestyle, but staying within the “fit” zone generally supports better metabolic health, hormone balance, and longevity.
Always measure on bare skin for accuracy. Take each measurement twice and average them. Even small tape errors can shift your body fat percentage by 1–2%.
There are several scientific methods for estimating body fat. Each has pros and trade-offs:
Among these, the body fat US Navy calculator gives the best balance between convenience and accuracy. That’s why it’s used in most army body fat calculators and USMC body fat calculators worldwide.
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |