Body Fat Calculator
Estimate your body fat percentage, fat mass and lean mass using the U.S. Navy tape-measure method.
About this calculator
This free body fat calculator uses the U.S. Navy circumference method to estimate your body fat percentage from a few tape measurements. It also converts that percentage into fat mass and lean mass using your weight.
How it works
The formula combines your height with your neck and waist measurements (and hips for women). It needs no calipers or scales beyond a tape measure and your body weight, which makes it easy to repeat and track over time.
Body fat categories
- Essential: 2–5% (men), 10–13% (women)
- Athletes: 6–13% (men), 14–20% (women)
- Fitness: 14–17% (men), 21–24% (women)
- Average: 18–24% (men), 25–31% (women)
For a broader picture of healthy weight, try the BMI calculator or plan intake with the calorie calculator.
Frequently asked questions
It estimates body fat from body circumference measurements — neck and waist for men, plus hips for women — together with your height. It is a quick, tape-only method that correlates reasonably well with more expensive tests.
Measure your waist at the belly button, your neck just below the larynx, and (for women) your hips at their widest point. Keep the tape snug but not tight, and measure without holding your breath.
General fitness ranges are roughly 14–17% for men and 21–24% for women. Essential fat is about 2–5% for men and 10–13% for women; athletes are usually below the fitness range.
It is an estimate, typically within a few percent of a DEXA scan for most people. Very muscular or very lean bodies may see larger differences.
No. Your measurements are used only in your browser and are never uploaded.
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