Body Fat Percentage Calculator
The U.S. Navy tape method — a few measurements give a solid body-fat estimate, no calipers needed.
How the estimate works
The U.S. Navy method estimates body fat from the circumference of body parts where fat and lean mass differ most. It needs only a tape measure, and the measurements are fed into these formulas (all in 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
Metric entries are converted to inches first, so both unit modes give the same answer.
Body fat categories
| Category | Men | Women |
|---|---|---|
| Essential | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| High | 25%+ | 32%+ |
FAQ
How accurate is this?
The Navy method is usually within about 3–4% of a DEXA scan for most people. Measuring carefully and the same way each time matters more than anything else.
Where exactly do I measure?
Neck: just below the larynx, tape sloping slightly down at the front. Waist: at the navel for men, at the narrowest point for women. Hip (women): at the widest point. Keep the tape level and snug.
Why does the women's formula need a hip measurement?
Fat distribution differs between sexes, so the women's equation adds the hip circumference to capture it and stay accurate.