Body Fat Calculator

What is body fat percentage?

Body fat percentage is the share of your total body weight that is fat, with the rest being lean mass (muscle, bone, organs, and water). It is a more informative health and fitness metric than weight or BMI alone, because it distinguishes fat from muscle. This tool estimates it three ways: the US Navy tape method, a BMI-based method, and the Jackson-Pollock skinfold method.

Healthy ranges

Healthy body-fat ranges differ by sex because women naturally carry more essential fat. As general guidance, for men roughly 10 to 20% is fit and under about 6% is dangerously low; for women roughly 18 to 28% is fit and under about 14% is dangerously low. Athletes often sit at the lower end. These bands are approximate and vary with age and individual factors.

Comparing the measurement methods

Each method trades accuracy for convenience. The Navy tape method uses circumference measurements and is easy to repeat at home. The skinfold method uses caliper readings and can be more accurate with good technique. The BMI method is the roughest, since it only estimates from height and weight. The gold-standard methods (DEXA scans and hydrostatic weighing) are more precise but require a lab.

Track the trend, not the single number

Any home estimate carries a margin of error, so the most useful thing is consistency: measure the same way, at the same time of day, every few weeks, and watch the direction over time rather than fixating on one reading. Lean body mass (your weight minus fat mass) is a helpful companion number when your goal is to lose fat while keeping muscle.

Estimates are for general information only and are not medical advice. Consult a healthcare professional for an accurate assessment.