Body Fat Calculator
Estimate body fat percentage using the trusted U.S. Navy method.
Measurements
Body fat
20.7%
- Fat mass
- 15.5 kg
- Lean mass
- 59.5 kg
Estimated with the U.S. Navy circumference method. It's a good tape-measure estimate but less precise than a DEXA scan or hydrostatic weighing.
About the Body Fat Calculator
This calculator estimates your body fat percentage using the U.S. Navy circumference method — a tape-measure technique the military uses because it's quick, free and reasonably accurate. It compares measurements of your neck and waist (and hips for women) against your height to estimate the proportion of your weight that is fat.
Body fat percentage is often more useful than BMI because it distinguishes fat from muscle. Two people can share a BMI but have very different body compositions. The result is placed into categories — essential fat, athletes, fitness, average and obese — which differ between men and women because women naturally carry more essential fat.
For the most accurate reading, measure with a flexible tape kept snug but not tight, and take each measurement at the same point a couple of times. This is an estimate; methods like DEXA scans are more precise but far less convenient.
Frequently asked questions
How do I measure for the Navy method?
Measure your neck just below the larynx and your waist at the navel (men); women also measure the hips at their widest point. Keep the tape level and snug, enter the figures with your height, and the calculator does the rest.
Is the Navy method accurate?
It's a good practical estimate, typically within a few percent of more advanced methods for most people, though less reliable at the extremes of body composition. For clinical accuracy, a DEXA scan or hydrostatic weighing is the gold standard.
Why are the categories different for men and women?
Women naturally carry more essential body fat — needed for hormonal and reproductive health — so the healthy ranges sit higher than for men. The calculator applies the appropriate category bands based on the sex you select.
What's a healthy body fat percentage?
For men the 'fitness' range is roughly 14–17% and 'average' 18–24%; for women it's about 21–24% and 25–31%. Athletes sit below these, and very low body fat can be unhealthy. Context and individual goals matter.
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