Body Fat Calculator
Estimate your body fat percentage using the US Navy method.
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Estimated Body Fat
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Fat Mass
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Lean Mass
About the Body Fat Calculator
This calculator uses the US Navy circumference method, developed by Hodgdon and Beckett (1984). It estimates body fat percentage from simple tape measure readings — no expensive equipment needed. The method is widely used by military and fitness professionals.
Body fat categories (American Council on Exercise)
- Men: Essential fat 2–5%, Athletes 6–13%, Fitness 14–17%, Acceptable 18–24%, Obese 25%+
- Women: Essential fat 10–13%, Athletes 14–20%, Fitness 21–24%, Acceptable 25–31%, Obese 32%+
How to take measurements
Measure at the same time each day (morning is best). Use a flexible tape measure. For waist, measure at the narrowest point (women) or navel level (men). For neck, measure just below the larynx. For hips (women), measure at the widest point.
Frequently Asked Questions
How is body fat percentage calculated?
The US Navy method uses neck, waist, and hip measurements along with height to estimate body fat. The formula differs for men and women. The BMI method uses body mass index as a proxy.
What is a healthy body fat percentage?
For men, 6–24% is generally healthy; 25% and above is considered excess fat. For women, 16–30% is healthy; above 31% is considered excess. Athletes typically have lower percentages.
Is the Navy method accurate?
The Navy method has a margin of error of about 3–4 percentage points. It is more accurate than BMI-based estimates but less precise than DEXA scans or hydrostatic weighing.
Where should I measure my waist?
Measure your waist at the narrowest point (for women) or at the navel level (for men). Stand relaxed, do not suck in your stomach, and measure after exhaling normally.