Body Fat Calculator
Free body fat calculator using the U.S. Navy tape-measure method. Estimate your body fat percentage, fat mass and lean mass from simple measurements.
Your Measurements
Body Fat Percentage
16.9%
Composition
How It Works
Choose units and gender
Select metric or imperial, then your gender — women also enter a hip measurement.
Enter your measurements
Measure height, neck and waist (and hip for women) with a tape, plus your weight, and type them in.
Read your body fat
See your estimated body fat percentage, category, fat mass and lean mass instantly.
Body fat percentage tells you how much of your total weight is fat versus lean tissue like muscle, bone and water. It is often a more meaningful health and fitness marker than weight or BMI alone, because two people of the same weight can have very different amounts of body fat.
This calculator uses the U.S. Navy circumference method, which estimates body fat from tape measurements of the neck, waist and (for women) hips relative to height. From your weight it also splits your body into fat mass and lean mass. Because it relies on consistent measuring, use the same technique each time to track changes reliably.
Frequently Asked Questions
How does the U.S. Navy method work?
It estimates body fat from the circumference of your neck, waist (and hip for women) relative to your height, using a logarithmic formula developed by the Naval Health Research Center. It requires only a tape measure rather than calipers or a scan.
How should I take the measurements?
Measure your neck just below the larynx, your waist at the navel for men and at the narrowest point for women, and (for women) the hips at the widest point. Keep the tape level and snug but not compressing the skin for the most consistent results.
What is a healthy body fat percentage?
General categories for men are: essential 2–5%, athletes 6–13%, fitness 14–17%, average 18–24%, and obese 25%+. For women they run higher: essential 10–13%, athletes 14–20%, fitness 21–24%, average 25–31%, and obese 32%+.
How accurate is this estimate?
The Navy method is convenient but typically within a few percentage points of more precise methods like DEXA, and accuracy depends on measurement technique. Results are estimates for general information only and are not medical advice.
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