📏 Body Fat Calculator
Estimate your body fat percentage using the widely-used US Navy circumference method, based on a few simple tape measurements.
What this calculator estimates
This tool estimates your body fat percentage using the US Navy circumference method, a formula developed for the US Navy that uses tape-measure measurements instead of specialized equipment like calipers or scans. It uses your height, neck, and waist (plus hip for women) to estimate how much of your body weight is fat versus lean mass.
How the formula works
The Navy method uses a logarithmic formula based on the circumference measurements you provide. For men, it uses waist and neck measurements; for women, it also factors in hip measurement, since fat distribution patterns differ between sexes. For the most accurate reading, measure your waist at the navel, your neck just below the larynx, and your hips at their widest point, and use a flexible tape measure held snug but not tight.
This is an estimate, not a diagnostic measurement. Body composition scans (like DEXA) or skinfold calipers performed by a trained professional are more accurate. This tool is for general fitness planning and educational purposes only.