Body Fat Calculator (US Navy Method)

About this calculator

The US Navy method estimates body fat from circumference measurements — no calipers or scans needed. Men measure neck and waist; women also measure hips (the hip field is ignored for men). Measure the waist at the navel, the neck below the larynx, and the hips at the widest point, with the tape level and snug but not compressing.

Rough reference ranges for adults: essential fat sits below about 5% (men) / 13% (women); athletes typically 6–13% / 14–20%; fitness 14–17% / 21–24%; average 18–24% / 25–31%. Tape-based estimates are usually within 3–4 percentage points of lab methods — good for tracking change over time, less exact as a one-off number.

The waist must measure larger than the neck for the formula to work. Results are informational, not a medical assessment.