Body Fat Calculator

Estimate your body fat percentage with the US Navy method — just a tape measure and a few numbers.

centimetres

circumference (cm)

circumference (cm)

Please enter valid measurements. Check that waist is larger than neck.

Body Fat
—%
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What is the body fat calculator?

This tool estimates your body fat percentage — the share of your total body weight that is fat tissue — using the US Navy circumference method. Unlike weight or BMI, body fat percentage tells you about your actual body composition, which is a far better indicator of fitness and health. The method needs only a tape measure and takes under a minute, yet it correlates closely with more expensive techniques like skinfold calipers.

How the US Navy method works

Developed by the Naval Health Research Center, this method uses the circumference of your neck, waist (and hips for women) along with your height to estimate body fat. The measurements capture where fat is typically stored, and a validated formula converts them into a percentage. Because it relies on measurements rather than total weight, it is not thrown off by muscle mass the way BMI can be.

How to measure correctly

  • Neck — measure just below the larynx (Adam's apple), tape sloping slightly downward to the front.
  • Waist — men measure at the navel; women at the narrowest point of the waist.
  • Hip (women only) — measure around the widest part of the hips and buttocks.

Measure on bare skin, keep the tape snug but not tight, and exhale normally before reading. Take each measurement twice and use the average for best accuracy.

Body fat categories

General ranges from the American Council on Exercise (ACE):

  • Men — Essential 2–5%, Athletes 6–13%, Fitness 14–17%, Average 18–24%, Obese 25%+
  • Women — Essential 10–13%, Athletes 14–20%, Fitness 21–24%, Average 25–31%, Obese 32%+

Frequently asked questions

How accurate is the US Navy body fat method?

The US Navy circumference method is typically accurate to within 3–4% of clinical methods for most people, making it one of the most reliable at-home estimates. Accuracy depends on measuring consistently at the right spots. It is less precise for very lean or very obese individuals.

Where do I measure my waist, neck, and hips?

Measure your neck just below the larynx, your waist at the navel for men or at the narrowest point for women, and your hips (women only) at the widest point. Keep the tape snug but not compressing the skin, and measure on bare skin after exhaling normally.

What is a healthy body fat percentage?

For men, 14–24% is generally considered healthy; for women, 21–31%. Athletes often sit below these ranges. Essential fat (the minimum for health) is about 2–5% for men and 10–13% for women.

Why is body fat different for men and women?

Women naturally carry more essential fat than men for hormonal and reproductive functions, so healthy ranges are higher. The US Navy formula also adds a hip measurement for women to account for typical fat distribution.

Is body fat percentage better than BMI?

Body fat percentage is more informative than BMI because it measures actual fat rather than total weight, so it isn't fooled by high muscle mass. However, BMI is quicker and needs no tape measure. Using both gives a fuller picture.

Disclaimer: This calculator provides an estimate for general informational purposes only and is not a clinical measurement or medical advice. For precise body composition analysis, consult a healthcare or fitness professional.

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