What Is Body Fat Percentage?
Body fat percentage is the proportion of your total body weight that is made up of fat tissue. Unlike BMI, it directly distinguishes fat from lean mass (muscle, bone, organs, water), making it a more precise indicator of body composition and health. A certain amount of fat is essential for hormonal function, insulation, and organ protection — but excess body fat raises the risk of cardiovascular disease, type 2 diabetes, and metabolic syndrome.
The US Navy Method
This calculator uses the US Navy circumference method, one of the most accessible and reasonably accurate techniques that doesn’t require expensive equipment. It uses body circumference measurements to estimate fat percentage using a validated logarithmic formula.
Women: BF% = 495 ÷ (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450
How to Take Accurate Measurements
For best results: measure your waist at the navel (men) or narrowest point (women); measure your neck just below the larynx; measure your hips at the widest point. Use a flexible tape, stand straight, and take each measurement twice and average them.
Body Fat Categories
Essential fat (the minimum needed for survival) is around 2–5% for men and 10–13% for women. Athlete-level body fat runs 6–13% for men and 14–20% for women. The average healthy adult falls in the 18–24% range for men and 25–31% for women. Above 25% (men) or 32% (women) is generally considered obese.