Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy tape-measure method. Enter a few circumference measurements to get your body fat percentage, category, and fat-versus-lean mass.
How to use it
Measure your neck and waist (and hips for women) with a tape measure, add your height, and the calculator estimates your body fat percentage and category. Add your weight to also see your fat mass and lean mass.
The Navy method is free and repeatable, which makes it good for tracking change over time. It's an estimate, not a clinical scan — for best results, measure the same way each time: tape snug and level, muscles relaxed, no breathing in.
Frequently asked questions
How does the Navy body fat method work?
It estimates body fat from body circumferences — neck and waist for men, plus hips for women — together with height. It's free, needs only a tape measure, and is reasonably accurate for most people.
Where exactly do I measure?
Measure your neck just below the larynx, your waist at the navel for men or the narrowest point for women, and hips at the widest point for women. Keep the tape snug and level, and don't suck in.
Is it as accurate as a DEXA scan?
No. DEXA and hydrostatic weighing are more precise. The Navy method is a solid, repeatable estimate for tracking change — measure the same way each time and watch the trend rather than a single reading.
BriskToolbox provides estimates for general information only and is not medical advice. Talk to a healthcare professional about your individual health.