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Body Fat Calculator
Body fat percentage, fat mass, and lean body mass from tape measurements or skinfolds.
Results
- Body fat
- 26.1%
- Category
- Average
- Fat mass
- 18.3 kg (40 lb)
- Lean body mass
- 51.7 kg (114 lb)
- Waist-to-height
- 0.47 (healthy)
US Navy method
Body fat = 26.1%
Lean mass = 70 − 18.3 = 51.7 kg
Lean body mass feeds the Katch-McArdle Formula on the BMR and calorie calculators.
Body fat percentage is the share of your weight that is fat rather than muscle, bone, and water. This calculator uses the US Navy circumference method or a 3-site skinfold sum.
It returns body fat %, fat mass, lean body mass, a category, and — from your waist — the waist-to-height ratio.
How to measure body fat
To measure body fat with the Navy method, tape your neck and waist (and hips for women) at the widest relaxed point, then read the percentage. Keep the tape level and snug.
Healthy ranges run about 10–20% for men and 18–28% for women; athletes sit lower.
Frequently asked questions
Healthy body fat is roughly 10–20% for men and 18–28% for women. Essential fat is 2–5% for men and 10–13% for women.
Within about 3–4% of a DEXA scan for most people. Consistent tape placement matters more than the method.
Lean body mass is your weight minus fat mass — muscle, bone, organs, and water. It drives the Katch-McArdle BMR equation.
Results are estimates based on population averages and are not medical advice. Consult a doctor or registered dietitian nutritionist (RDN) before making large changes to your diet, especially for deficits over 2 lb (0.9 kg) per week, during pregnancy or nursing, or for anyone under 18.