Free body fat calculator using the US Navy method: estimate your body fat percentage for men and women from simple circumference measurements.
Body fat percentage is the proportion of your total weight that comes from fat. It is a better indicator of fitness than BMI alone because it distinguishes between muscle and fat. This calculator uses the US Navy circumference method, which is based on height and body measurements.
For men, 6-24% is generally healthy (athletic 6-13%, fitness 14-17%, average 18-24%); for women, 14-31% (athletic 14-20%, fitness 21-24%, average 25-31%). Essential fat is higher in women (10-13%) because of reproductive biology.
It is a well-validated field method, usually within 3-4% of DEXA or hydrostatic weighing for most people. Accuracy depends on consistent measurement technique.
The female formula includes the hip measurement because women store more fat around the hips and thighs; waist and neck alone underestimate body fat for women.
Yes. Use a flexible tape and follow the measurement instructions carefully. Calipers and smart scales are alternatives, but consistency matters more than which method you use.
BMI cannot distinguish muscle from fat. Two people with the same BMI can have very different body fat percentages, and higher body fat at the same BMI is linked to higher health risk.
Essential fat is the minimum needed for normal physiological function, including hormones and cell membranes. It is about 3-5% for men and 10-13% for women; dropping below it is dangerous.