Body Fat Calculator (US Navy)

Estimate your body fat percentage using a widely referenced circumference method.

How It Works (US Navy Method)

The US Navy method estimates body fat based on circumference measurements. It uses logarithmic relationships between height and girths.

  • Male: 495 / (1.0324 − 0.19077·log10(waist − neck) + 0.15456·log10(height)) − 450
  • Female: 495 / (1.29579 − 0.35004·log10(waist + hip − neck) + 0.22100·log10(height)) − 450

How to Measure

  1. Height: barefoot, upright posture
  2. Neck: just below the larynx, tape slightly angled downward in front
  3. Waist: at navel level for males; narrowest waist for females
  4. Hip (females): at the widest part of the buttocks

Notes & Limitations

  • Hydration and measurement technique affect results
  • Consider taking 2–3 measurements and averaging
  • For athletic or atypical body types, method may under/over estimate