Body Fat Calculator
Estimate body fat percentage using the U.S. Navy method.
Quick answer
Body fat percentage is the share of your weight that's fat. The U.S. Navy method estimates it from height and circumference measurements (neck and waist, plus hips for women). Track the trend rather than a single reading; healthy ranges vary by sex and age.
Estimated body fat
16.9%
U.S. Navy circumference method
Fitness range
14–17%
Athlete range
6–13%
How the Navy method works
The U.S. Navy formula estimates body fat from circumferences — neck and waist for men, plus hips for women — against height. Measured carefully (tape level, no sucking in), it lands within ±3–4% of lab methods for most people, which is comparable to consumer bioimpedance scales.
Reference ranges
The American Council on Exercise brackets: essential fat 2–5% (men) / 10–13% (women); athletes 6–13% / 14–20%; fitness 14–17% / 21–24%; average 18–24% / 25–31%. Trends matter more than any single reading — measure at the same time of day, weekly.
Frequently asked questions
- How does the Body Fat Calculator work?
- Body fat percentage is the share of your weight that's fat. The U.S. Navy method estimates it from height and circumference measurements (neck and waist, plus hips for women). Track the trend rather than a single reading; healthy ranges vary by sex and age.
- Is the Body Fat Calculator free to use?
- Yes. The Body Fat Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
Sources & methodology
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