This calculator uses the U.S. Navy circumference method — based on neck, waist (and hip, for women), height, and weight — to estimate body fat percentage without calipers or a DEXA scan. It's an estimate, not a lab-precise measurement, but it's a reasonably reliable way to track changes over time using just a tape measure.
Example: a male, 5'11", 165 lbs, with a 15" neck and 32" waist, gets an estimated body fat percentage — track these same measurements every few weeks to see real trend changes, since the method is more reliable for relative change than an exact absolute number.
Body fat percentage is the proportion of your body weight made up of fat tissue. It is a more accurate health indicator than weight alone because it distinguishes between fat mass and lean mass.
For men: essential fat 2–5%, athletic 6–13%, healthy 14–17%, acceptable 18–24%. For women: essential 10–13%, athletic 14–20%, healthy 21–24%, acceptable 25–31%.
This calculator uses the US Navy circumference method which estimates body fat from neck, waist, and hip measurements. It is a reliable field estimation method that requires only a measuring tape.
BMI uses only height and weight, making it less precise than body fat percentage, which directly measures the proportion of fat in your body. Two people with the same BMI can have very different body fat levels.
Body fat percentage is the proportion of your body weight made up of fat tissue. It is a more accurate health indicator than weight alone because it distinguishes between fat mass and lean mass.
This calculator uses the US Navy circumference method, which estimates body fat from neck, waist, and hip measurements. It is a reliable field estimation method that requires only a measuring tape.
For men: essential fat 2-5%, athletic 6-13%, healthy 14-17%, acceptable 18-24%.
For women: essential fat 10-13%, athletic 14-20%, healthy 21-24%, acceptable 25-31%.
BMI uses only height and weight, making it less precise than body fat percentage, which directly measures the proportion of fat in your body. Two people with the same BMI can have very different body fat levels.