Body Fat Calculator

Estimate your body fat percentage with a tape measure using the US Navy circumference method.

How to use the Body Fat Calculator

  1. Select your sex and units.
  2. Measure and enter your height, neck and waist (women also enter hips).
  3. Add your weight to see fat mass and lean body mass.

The US Navy body fat formula

The method estimates body fat from circumferences, with all measurements in centimeters:

  • Men: 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450
  • Women: 495 ÷ (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450

How to measure

  • Neck: just below the larynx, tape sloping slightly down at the front.
  • Waist: men at the navel; women at the narrowest point.
  • Hips (women): at the widest point of the buttocks.

Body fat categories

Category Women Men
Essential fat 10–13% 2–5%
Athletes 14–20% 6–13%
Fitness 21–24% 14–17%
Average 25–31% 18–24%
Obese 32% and above 25% and above

This calculator gives general information for healthy adults. It is not medical advice. Talk to a doctor or registered dietitian before making significant changes to your diet or exercise.

Frequently asked questions

How accurate is the Navy body fat method?

It is usually within about 3 to 4 percentage points of laboratory methods such as DEXA when measurements are taken carefully.

What is a healthy body fat percentage?

Roughly 21–31% for women and 14–24% for men covers the fitness and average ranges. Athletes are typically lower.

Why do women need a hip measurement?

Women tend to store more fat around the hips, so the formula for women includes hip circumference to improve accuracy.

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