Body Fat Percentage Calculator
US Navy tape method: body fat, fat and lean mass.
US Navy circumference method, which lands within ~3–4% of DEXA scans: it estimates fat percent from body shape, no fancy scales needed. Measure the waist at the navel level, snug but not tight. Women also need a hip measurement.
How to use the Body Fat Percentage tool
- Enter your body fat in the fields above.
- Adjust any slider or type an exact number — the answer updates as you go.
- Copy the result and close the tab. Nothing you entered was sent anywhere.
About the Body Fat Percentage tool
Uses the US Navy circumference method — waist, neck, height and hips for women — for a body fat estimate within about 3–4 points of a DEXA scan, plus fat and lean mass split from your weight.
Women need the hip measurement because the formula differs; that is method design, not a mistake in the inputs.
Everything runs locally in your browser: no data is uploaded, no account is needed, and it works offline once the page has loaded.
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