Estimate your body fat percentage from simple tape measurements using the U.S. Navy circumference method.
Uses the U.S. Navy circumference method. Measure the neck just below the larynx, the waist at the navel, and for women the hip at the widest point. It is an estimate; skinfold calipers or a DEXA scan are more accurate.
It estimates body fat from body circumferences. Men use height, neck and waist; women add the hip. The measurements go into a formula validated against more precise methods, giving a result within a few percent for most people.
Use a flexible tape, pulled snug but not tight. Measure the neck just below the larynx, the waist horizontally at the navel, and the hip (women) at the widest point. Take each measurement twice and average them for consistency.
Ranges differ by sex. For men, roughly 6 to 13% is athletic, 14 to 17% is fit, and 18 to 24% is average. For women the numbers are higher because of essential fat, with athletic around 14 to 20%. The tool labels your estimate accordingly.