Results are estimates for healthy adults unless stated, and are not medical advice. Your doctor or a registered dietitian can give advice for your situation.
Your weight alone can’t tell fat from muscle. Body fat percentage gives a better picture of your health and fitness. This calculator uses the US Navy method, which needs only a tape measure.
How to measure yourself
- Height: without shoes, standing straight.
- Neck: just below the larynx (Adam’s apple), tape sloping slightly down at the front.
- Waist: men at the navel; women at the narrowest point. Breathe out normally, don’t suck in.
- Hips (women): at the widest part of the buttocks.
Measure on bare skin, keep the tape level and snug without squeezing, and take each measurement twice.
The US Navy formula
All measurements are in centimetres:
- Men: body fat % = 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450
- Women: body fat % = 495 ÷ (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450
Body fat ranges
| Category | Women | Men |
|---|---|---|
| Essential fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Average | 25–31% | 18–24% |
| Above healthy range | 32%+ | 25%+ |
Example
A man 178 cm tall with a 38 cm neck and an 86 cm waist has an estimated body fat of about 17%, in the fitness range.
Frequently asked questions
How accurate is the US Navy method?
It is usually within about 3–4 percentage points of lab methods like DEXA scans, which is good enough to track changes over time with the same tape and technique.
Why do women have more body fat?
Women naturally carry more essential fat for hormonal and reproductive health, so healthy ranges are higher than for men.
Is body fat better than BMI?
Body fat separates fat from muscle, so it is more useful for muscular people. Waist size on its own is also a strong health marker.
Sources
- Hodgdon JA, Beckett MB – Naval Health Research Center (1984)
- U.S. Department of Defense – body composition standards
- American Council on Exercise (ACE) – body fat percentage norms