Body Composition Body Composition Navy Method Circumference

Body Fat Percentage Calculator (US Navy)

🧮 About this calculator

The U.S. Navy circumference method estimates body fat percentage from a small number of measurements (height, neck, waist, and — for women — hips). It's a free, at-home alternative to DEXA or hydrostatic weighing.

Inputs
📘 Formula & explanation
Male: BF% = 495 / (1.0324 - 0.19077 * log10(waist - neck) + 0.15456 * log10(height)) - 450

The U.S. Navy method uses circumference measurements and a logarithmic regression to estimate body density, which is then converted to body fat percentage via the Siri equation (BF% = 495/density - 450).

References
  • U.S. Navy Physical Readiness Program
  • Hodgdon & Beckett (1984)
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