Body Fat Calculator

Estimate body fat percentage with a tape measure, using the US Navy circumference method.

Units
Fractions and decimals both work.
Body fat
Category (ACE)
Fat mass
Lean mass
Note
Work

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The US Navy Body Fat Formula

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

Measurements in inches (Hodgdon and Beckett, Naval Health Research Center, 1984). Measure the neck just below the larynx, the waist at the navel (men) or narrowest point (women), and hips at the widest point.

Category (ACE)WomenMen
Essential fat10–13%2–5%
Athletes14–20%6–13%
Fitness21–24%14–17%
Average25–31%18–24%
Obese32%+25%+

Worked Example

Tips

Measure three times and average, with the tape snug but not compressing the skin. Results are estimates.