Body Fat Calculator

Estimate your body fat percentage with the US Navy circumference method. Enter your sex, age, height, weight and circumference measurements in metric or imperial.

Choose your unit system, then enter your sex, age, height, weight and circumference measurements (neck, waist, and hip for females). The US Navy method estimates body fat percentage, fat mass and lean body mass.

Body fat
Category
Fat mass
Lean body mass
BMI (for reference)

The US Navy body fat method estimates body fat percentage from circumference measurements. It's more informative than BMI because it distinguishes fat from lean mass, though it's still an estimate — a DEXA scan is the gold standard.

US Navy equations

  • Men: 495 / (1.0324 − 0.19077×log(waist − neck) + 0.15456×log(height)) − 450
  • Women: 495 / (1.29579 − 0.35004×log(waist + hip − neck) + 0.22100×log(height)) − 450

Measure neck below the larynx, waist at the navel, and hip at the widest point.

Examples

  • A 10% point drop in body fat is a major, visible change
  • Healthy ranges: men 10–20%, women 18–28% (varies by age)
  • The method is least reliable for very muscular or very lean people

Frequently asked questions

How accurate is the US Navy method?

It's typically within 3–4% of DEXA for most people. Accuracy depends on careful, consistent measuring — measure at the same spots each time, ideally by the same person.

Why does it ask for hip only for females?

The female equation includes hip circumference; the male equation does not. The field appears only when 'Female' is selected.

Just for the giggles, much love.
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