Body Fat Calculator

Estimate body fat % with the US Navy tape method.

Loading the interactive tool… It runs in your browser — if it doesn't appear, enable JavaScript.

Estimate body fat percentage from tape measurements using the US Navy circumference method — the formula the military uses for fitness assessment because it needs no equipment beyond a tape measure. Men measure neck and waist; women add hips. Accuracy is around ±3–4%, which makes it most valuable for tracking change over time rather than as a single absolute number.

Frequently asked questions

Where exactly do I measure?

Neck: just below the larynx, tape sloping slightly down to the front. Waist: at the navel for men, at the narrowest point for women. Hips (women): at the widest point. Tape snug but not compressing the skin, and measure at the same time of day each time.

How accurate is the Navy method versus a DEXA scan?

Studies put it within 3–4% of DEXA for most body types — remarkably good for a tape measure. It drifts most for very muscular or very lean physiques. Consistency of measurement matters more than the absolute figure.

What's a healthy body fat percentage?

Rough fitness-industry bands: men — athletes 6–14%, fit 14–18%, average 18–25%; women — athletes 14–21%, fit 21–25%, average 25–32%. Women's essential fat is higher by design; very low percentages are unhealthy for either sex.