Health · Body composition
A tape measure, not a diagnosis.
Estimate body fat percentage with the US Navy circumference formula in US or metric units.
Tape measurements
Measure relaxed, without pulling the tape tight.
Estimated body fat
21.1%
Within the typical adult male range.
Category
Average
Method
US Navy
The US Navy formula is a circumference estimate. It can differ from DEXA, hydrostatic weighing or a trained assessor. Not medical advice.
Good to know
The result is a guide, not a guarantee.
This calculator runs entirely in your browser. Check the assumptions, keep the inputs realistic, and use the result as a starting point for a decision.
Circumference estimates have meaningful error. Not medical advice or a substitute for a clinical assessment.
How does the US Navy method work?
It estimates body fat from circumference measurements. For men it uses neck and waist; for women it adds hip. Height is used to scale the result. The formula is a statistical estimate, not a direct measurement.
Where should I measure?
Measure the neck below the larynx, the waist at the navel for men or the narrowest point for women, and the hips at the widest point. Keep the tape level and relaxed.
Why is my result different from a smart scale?
Smart scales use bioelectrical impedance, which is sensitive to hydration and can differ substantially. DEXA and hydrostatic weighing are more precise but still have error ranges.
What do the categories mean?
The ranges are broad reference bands for adults: essential fat, athletic, fitness, average and obese. They are not clinical diagnoses and do not capture muscle mass or health markers.