Body Fat Calculator

Body fat percentage is the proportion of your total body weight that comes from fat tissue, as opposed to lean mass (muscle, bone, water, and organs). For example, a person weighing 60 kg with 27% body fat carries approximately 16.2 kg of fat and 43.8 kg of lean mass. It is a far more precise indicator of body composition than weight or BMI alone.

This calculator uses the U.S. Navy method, which estimates body fat percentage from body circumference measurements — waist, neck, and hip (for women) — along with height. These measurements are plugged into a logarithmic formula developed by the U.S. Navy to provide a quick, equipment-free body fat estimate.

Healthy body fat ranges differ significantly by gender. For men: Essential fat is 2–5%, Athletic is 6–13%, Fit is 14–17%, Average is 18–24%, and Obese is 25%+. For women: Essential fat is 10–13%, Athletic is 14–20%, Fit is 21–24%, Average is 25–31%, and Obese is 32%+. Women naturally carry more essential fat due to hormonal and reproductive physiology.

The U.S. Navy method is a circumference-based body fat estimation formula developed for military fitness assessments. Studies show it has a margin of error of roughly ±3–4% compared to gold-standard methods like DEXA scans. It is considered reliable for general population use and significantly more informative than BMI, though measurement accuracy is critical to getting a meaningful result.

In most cases, yes. BMI only uses height and weight, making it unable to differentiate between muscle and fat. Body fat percentage directly measures fat mass versus lean mass, making it far more elucidative of your actual body composition. A muscular athlete and an sedentary person can share the same BMI but have vastly different body fat percentages and health profiles.

No — it is a circumference-based estimate. Factors that can affect accuracy include tape placement, posture during measurement, hydration level, time of day, and individual body shape variations. For the most consistent results, measure in the morning before eating, keep the tape parallel to the ground, and take each measurement 2–3 times and use the average.

Fat mass is the total weight of all fat tissue in your body, including essential fat (needed for organ protection and hormonal function) and storage fat. Lean mass is everything else — muscles, bones, organs, water, and connective tissue. Tracking both numbers, not just total weight, gives a much clearer picture of whether you are losing fat or muscle during a diet.

Yes — they measure different things. Body fat percentage includes all fat in your body. Visceral fat specifically refers to fat stored deep inside the abdominal cavity, surrounding your organs. Even someone with an average body fat percentage can carry dangerous levels of visceral fat if their waist measurement is high. A large waist circumference (above 80 cm for women, 94 cm for men) is an independent risk marker for metabolic disease.

The most effective approach is a combination of a moderate calorie deficit, adequate protein intake (to preserve lean mass), and regular resistance training. Cardio accelerates fat loss but without strength training, you risk losing muscle alongside fat. Sustainable fat loss of 0.5–1% body fat per month is realistic and minimizes the metabolic adaptation that comes with aggressive cutting.

Yes — going below essential fat levels is dangerous. For men, dropping below 4–5% and for women below 10–12% can disrupt hormonal function, impair immune response, cause bone density loss, and lead to serious health complications. Female athletes who drop too low often experience a condition called Female Athlete Triad — a combination of low energy availability, loss of menstrual cycle, and bone deterioration.

More precise methods include DEXA scan (dual-energy X-ray absorptiometry) — considered the gold standard with ±1–2% accuracy; Hydrostatic weighing (underwater weighing); Bod Pod (air displacement); and Skinfold calipers used by a trained professional. These methods are more accurate than circumference-based calculators but require specialized equipment or clinical settings.