Body Fat % Estimator

Estimate your body fat percentage using the US Navy method. Requires just a few circumference measurements.

Sex
Biological sex
Units
Unit system
Height
ft
in
Neck Circumference
in
Waist Circumference (at navel)
in
Body Weight (optional, for mass breakdown)
lbs
How is this calculated?

This calculator uses the US Navy body fat estimation method, which derives body fat percentage from circumference measurements and height. It was developed by Hodgdon and Beckett at the Naval Health Research Center.

For males:

BF% = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76

For females:

BF% = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387

All measurements are in inches for the formula. Metric values are converted to inches before calculation.

Body Fat Categories (ACE):

Male: Essential Fat: 2–5%  |  Athletes: 6–13%  |  Fitness: 14–17%  |  Average: 18–24%  |  Obese: 25%+

Female: Essential Fat: 10–13%  |  Athletes: 14–20%  |  Fitness: 21–24%  |  Average: 25–31%  |  Obese: 32%+

This is an estimation method and may not be perfectly accurate for all individuals. Factors such as muscle mass distribution, age, and ethnicity can affect accuracy. For a clinical measurement, consider DEXA scanning or hydrostatic weighing.

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