Body Fat Calculator — US Navy Tape Method

How to use

1. Measure with a tape — neck below the larynx; waist at the navel (men) or narrowest point (women); hips at the widest point (women only).
2. Enter your numbers — pick metric or imperial, male or female.
3. Read your estimate — body fat %, fat/lean mass split and where you sit in the ACE reference ranges.

General information only — not medical, financial or legal advice. Figures cross-checked against public official sources (IRS / HMRC / NHS / WHO guidance); content last reviewed September 2026. For decisions that matter, confirm with a licensed professional in your country.

About this tool

Body fat percentage is a far better health signal than weight alone. This calculator implements the US Navy circumference method (the standard field test): log10-based equations using height, neck and waist for men, plus hip for women. You get estimated body fat %, your fat mass vs lean mass in kg/lb, the American Council on Exercise reference ranges (essential → athletic → average → obese) and a simple visual gauge. Tape measurements are estimates — consistency in measuring matters more than perfection.

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