Body Fat Calculator

cm
cm
Men: measure at the navel. Women: measure at the narrowest point.
cm
Measure just below the larynx (Adam's apple), sloping slightly downward
cm
Measure at the widest point of the hips/buttocks (required for women)
Health Updated 14 Jun 2026

Estimate your body fat percentage with the US Navy circumference method. Enter your sex, height, and a few tape measurements to see your body fat percentage, category, and healthy range.

Rates and fees change frequently. Always confirm the current figures with the official authority before relying on this result.
  • The US Navy method may be less accurate for very muscular or very lean individuals.
  • Hip measurement is required only for women.
  • Measurements should be taken at the same time each day for consistency.

Formula

Men: BF% = 86.01 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76 Women: BF% = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387 (All measurements in cm)
  • The US Navy method estimates body fat from body circumferences and height using a validated logarithmic formula.
  • Men need height, neck, and waist; women also need the hip measurement.
  • All measurements are in centimetres; the waist must be larger than the neck for the formula to work.
  • Healthy ranges are roughly 10–20% for men and 18–28% for women, varying with age and fitness.
  • It is an estimate — calipers, bioimpedance, and DEXA can give different (often more precise) results.

Woman: 170 cm, waist 83, neck 37, hip 95

Inputs
  • Sex: female
  • Height: 170 cm
  • Waist: 83 cm
  • Neck: 37 cm
  • Hip (women only): 95 cm

Plugging these into the women's Navy formula gives about 28% body fat, at the upper end of the fitness/acceptable range.

Frequently asked questions

How does the US Navy body fat method work?
It uses your height and tape measurements of the neck, waist, and (for women) hips in a logarithmic formula to estimate body fat percentage.
How do I measure correctly?
Use a snug, level tape: neck below the larynx, waist at the navel for men or the narrowest point for women, and hips at the widest point.
How accurate is it?
It is reasonably accurate for average builds but less so for very muscular or very lean people. Measure consistently for the best tracking.
What is a healthy body fat percentage?
Roughly 10–20% for men and 18–28% for women is considered healthy, though athletes are often lower.
Why do women need a hip measurement?
Women's fat distribution differs, so the female formula includes hips to improve accuracy.

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