Body Fat Calculator
US Navy circumference method. Requires a soft tape measure and 60 seconds. More predictive than BMI for athletic builds.
Body fat
Estimated body fat
0%
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Lean mass
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Fat mass
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Why circumference works
The US Navy developed this method in the 1980s as a quick alternative to skin-fold calipers for fitness assessments. It correlates well with hydrostatic weighing (the gold standard) — typically within ±3.5% — and beats BMI for athletes, who carry more muscle than the BMI tables assume.
What the categories mean
"Essential fat" is the bare minimum needed for hormonal and organ function — well below athletic levels and not a sustainable target. "Athletes," "Fitness," and "Acceptable" are progressively more lifestyle than performance-oriented bands.
Estimate — not medical advice
The numbers here are estimates built on population averages and published formulas. Any individual can sit well away from the average, so treat the output as a rough guide rather than a measurement of you specifically. It isn't a medical assessment, and it can't account for your history, medications, or anything a clinician would notice.