Health · Body composition

Body fat percentage calculator

Enter a few tape-measure circumferences to estimate your body fat percentage using the U.S. Navy method.

Your measurements

Measure waist at the navel and neck just below the larynx. Women also measure hips at the widest point.

Estimated body fat
—
—
Lean mass %—
MethodU.S. Navy

Rough sheet

step-by-step
BMI Calculator Ideal Weight Calculator Calorie Calculator Waist-to-Hip Ratio Calculator

About the U.S. Navy method

The U.S. Navy circumference method estimates body fat percentage from a handful of tape-measure readings — neck and waist for men, plus hip for women — run through a logarithmic formula the Navy developed as a fast field alternative to skinfold calipers or hydrostatic weighing. It's an estimate, typically accurate to within a few percentage points, not a lab-grade body composition test.

Frequently asked questions

It's a circumference-based estimate, typically within about 3-4% of more precise methods like DEXA scans. It's a convenient way to track trends over time rather than a lab-exact measurement.

Yes, toggle between metric (cm) and imperial (in) at the top of the calculator.