Calculate your body fat percentage using the US Navy method. Enter height, neck, and waist (and hips for women) for an accurate body fat estimate.
This calculator uses the US Navy Body Fat Formula — one of the most practical methods for estimating body fat at home. It was developed by Hodgdon and Beckett at the Naval Health Research Center and is used by the US military for fitness standards.
Men's formula: Body Fat % = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76
Women's formula: Body Fat % = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387
All measurements are at their narrowest/widest points: waist at the narrowest point (above the navel for men, at the navel for women), neck just below the larynx, hips at the widest point (women only). The formula has a margin of error of ±3–4% compared to DEXA scans.
The US Navy method estimates body fat from circumference measurements — neck and waist for men; neck, waist and hips for women — combined with height in logarithmic formulas. It needs only a tape measure and tracks change well over time.
A man 180 cm tall with a 90 cm waist and 38 cm neck scores roughly 20% body fat. American Council on Exercise ranges: essential fat 2–5% (men) / 10–13% (women); athletes 6–13% / 14–20%; average 18–24% / 25–31%.
How accurate is the tape method? Within ±3–4% of laboratory methods for most people — measure at the same time of day, tape snug but not compressing.
Why does body fat matter more than weight? Two people of equal weight can differ enormously in composition; health risk tracks visceral fat far better than scale weight alone.