Body Fat Calculator (US Navy Method)
Estimate body fat percentage from your neck, waist (and hip) measurements and height with the US Navy tape method, plus fat and lean mass.
For general information only — not medical advice. Results are estimates; talk to a doctor or qualified health professional about your own health.
How to use
- 1Measure your neck below the larynx, your waist at the navel (men) or narrowest point (women), and hips at the widest point (women).
- 2Enter the measurements, height and weight.
How it's calculated
US Navy (inches): men %BF = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76; women %BF = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387.
Frequently asked questions
How accurate is the Navy method?
Typically within about 3–4 percentage points of lab methods for most people. Measure carefully and at the same time of day.
What's a healthy body fat percentage?
Roughly 10–20% for men and 18–28% for women in general guidance. Athletes are often lower; very low levels can be unhealthy.
Where exactly should I measure?
Neck just below the Adam's apple; men's waist at the navel; women's waist at the narrowest point and hips at the widest point.