Body Fat Calculator
Estimate body fat percentage with a measuring tape (U.S. Navy method).
Runs in your browser — your data never leaves your device.
About the Body Fat Calculator
BMI only compares weight with height. Body fat percentage tells you how much of your weight is fat, which says more about fitness. All you need is a measuring tape.
The U.S. Navy method uses a few body measurements and is usually within a few percent of laboratory methods. Measure in the morning, without pulling the tape tight, and take the average of two or three measurements.
How to use the Body Fat Calculator
- Choose sex and units.
- Measure your height, your neck just below the voice box, and your waist (men: at the navel; women: at the narrowest point). Women also measure hips at the widest point.
- Click Calculate body fat.
Formula
Men: %BF = 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450.
Women: %BF = 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450.
(All measurements in cm.) Categories follow the American Council on Exercise.
Examples
- Man, 175 cm, neck 38 cm, waist 88 cm → 19.2% (average).
- Woman, 162 cm, neck 33 cm, waist 75 cm, hips 98 cm → 29.3% (average).
Frequently asked questions
Is this medical advice?
No. It gives a general estimate for information only. Please speak to a doctor or qualified health professional about your own situation.