Body Fat Calculator (US Navy Method)
Measure your neck, waist and (for women) hips with a tape, then enter them with your height to estimate your body fat percentage.
- Nothing you type is stored
- Free
- No signup
Estimated body fat
18.6%
Average- Fat mass
- 13 kg
- Lean mass
- 57 kg
An estimate for general information, not medical advice.
ACE body fat chart for your sex
| Essential fat | Athletes | Fitness | Average | Obese |
|---|---|---|---|---|
| 2–5% | 6–13% | 14–17% | 18–24% | 25%+ |
How to use
- Choose male or female and enter height and weight.
- Measure neck, waist (and hips for women) in cm.
- Read your body fat %, fat mass and category.
Good to know
US Navy formula (Hodgdon and Beckett, 1984), in cm. Men: 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450. Women: 495 ÷ (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450.
How to measure: neck just below the Adam's apple; waist at the navel for men and at the narrowest point for women; hips at the widest point. Keep the tape level and snug, not tight, and measure relaxed after breathing out. A 1 cm error at the waist moves the result by about 1%.
The tape method is usually within about 3–4% of lab methods like DEXA, so use it to track change over time rather than as an exact value. Categories come from the American Council on Exercise (ACE) chart.
Questions
What is a healthy body fat percentage?
On the ACE chart, about 14–24% for men and 21–31% for women is fitness to average. Men above 25% and women above 32% are in the obese range.
How accurate is the Navy method?
It is an estimate, usually a few percent off a DEXA scan. Measure the same way each time and watch the trend.
Where exactly should I measure my waist?
Men: horizontally at the navel. Women: at the narrowest part of the waist. Do not suck in your stomach.
Why does the calculator need my weight?
Only to split your weight into fat mass and lean mass. The body fat % itself comes from height and tape measurements.
Is my data stored?
No. Everything is calculated on your device.