Estimate your body fat percentage and lean body mass using the U.S. Navy circumference method, plus your ideal healthy range.
Load profiles to check calculations:
Fill in your physical circumferences to predict biological body fat levels.
Your body fat range falls within the standard classification criteria.
Understanding the difference between weight and body fat, and how to track fitness progress.
BMI (Body Mass Index) only evaluates total weight relative to height. It cannot tell the difference between heavy muscle mass and adipose fat tissue. Body Fat calculations measure actual body composition, giving a clearer picture of metabolic health and cardiovascular risk profiles.
Lean Body Mass (LBM) encompasses everything in your body except stored fat: muscles, bones, water, blood volume, and structural organs. Essential body fat is necessary for hormone manufacturing, cell protection, and vitamin absorption, while storage fat serves as energy reserves.
To improve your body composition:
For men, body fat % = 495 / (1.0324 - 0.19077 x log10(waist - neck) + 0.15456 x log10(height)) - 450, using centimeter measurements. For women, the formula also includes hip circumference: 495 / (1.29579 - 0.35004 x log10(waist + hip - neck) + 0.22100 x log10(height)) - 450.
Women naturally store more essential fat around the hips and pelvis, so the female formula factors in hip circumference to reflect that distribution, while the male formula relies only on neck and waist. The waist measurement must always exceed the neck measurement, and results are capped between 2% and 60% to stay within physiologically realistic bounds.
For a man who is 178 cm tall with a 38 cm neck and an 85 cm waist, the calculated density is about 1.0613, giving an estimated body fat of (495 / 1.0613) - 450, or roughly 16.4%. This places him in a generally lean, healthy range for an adult male.
Since body fat percentage reflects composition rather than just scale weight, compare your result against the BMI Calculator to see the difference, and use the Lean Body Mass Calculator to see how much of your weight is fat-free tissue.
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