Body Fat Calculator
Estimate your body fat percentage using the US Navy circumference method — no calipers needed.
Measuring Body Fat Without Expensive Equipment
The US Navy circumference method provides a reasonably accurate body fat estimate using just a flexible tape measure. It uses the anatomical principle that fat accumulates preferentially in specific areas (abdomen, hips) while lean tissue concentrations correlate with height. The formula compares circumferences to height to estimate fat mass percentage.
Body fat percentage is a superior fitness metric to BMI for most purposes. It directly measures the fat-to-muscle ratio rather than a proxy. Two people can have identical BMIs but dramatically different body compositions — one lean and muscular, one carrying excess fat. Body fat percentage captures this distinction.
For most people, tracking body fat percentage alongside weight provides the clearest picture of training and nutrition progress. During a successful cut, weight should decrease and body fat percentage should decrease. During a successful lean bulk, weight increases while body fat percentage stays relatively stable or increases only slightly. Seeing these trends in your numbers confirms your nutrition and training plan is working.