Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy circumference method. All you need is a tape measure — enter your neck, waist (and hip for women) measurements along with height.
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Result
American Council on Exercise ranges — Men: athletes 6–13%, fitness 14–17%, average 18–24%. Women: athletes 14–20%, fitness 21–24%, average 25–31%.
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- 1Enter sex in the form on the left.
- 2Fill in the remaining fields — the result updates automatically as you type.
- 3Review the highlighted result and the supporting breakdown on the right.
- 4Use Copy, Share or Print to save or send your result.
How the Navy method works
Developed for the U.S. military, the Navy method estimates body density from circumference measurements and height using logarithmic regression formulas, then converts density to body fat percentage. Studies put its accuracy within ±3–4% of underwater weighing for most people.
Measure the waist at the navel (men) or the narrowest point (women), the neck just below the larynx, and hips at the widest point. Take measurements relaxed, without compressing the skin, ideally at the same time of day.
Frequently Asked Questions
▸How accurate is the Navy body fat method?
Typically within 3–4 percentage points of laboratory methods. Its consistency makes it excellent for tracking change over time, even if the absolute number is slightly off.
▸What is a healthy body fat percentage?
Roughly 10–20% for men and 18–28% for women is commonly cited as healthy, with athletes lower. Essential fat minimums are ~3% for men and ~12% for women.