Enter your gender, age, height, weight, and body measurements (neck, waist, and hip for women) to get your estimated body fat percentage using the U.S. Navy Method. You'll see your body fat category, fat mass, lean body mass, and your ideal body fat range for your age.
Body Fat Percentage (Navy Method)
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Body Fat Category
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Fat Mass
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Lean Body Mass
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Ideal Body Fat for Age (Jackson & Pollock)
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Body Fat to Lose to Reach Ideal
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Body fat percentage is the proportion of your total body weight that is made up of fat tissue. It includes essential fat (needed for normal physiological functions) and storage fat. Unlike BMI, it directly reflects your body composition rather than just your weight relative to height.
The U.S. Navy Method uses circumference measurements — neck, waist, and hip (for women) — along with height to estimate body fat percentage using a logarithmic formula. For men: body fat % = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76. For women, the hip measurement is also included in the calculation.
According to the American Council on Exercise (ACE), a healthy body fat range for men is 14–17% (fitness) and 18–24% (average), while for women it's 21–24% (fitness) and 25–31% (average). Athletes typically have lower percentages — 6–13% for men and 14–20% for women.
Normal ranges differ by gender and age. Generally, essential fat is 2–5% for men and 10–13% for women. Being significantly above the average range may indicate increased health risks such as cardiovascular disease, diabetes, and metabolic syndrome. Consult a healthcare professional for a personalized assessment.
Tracking body fat gives a more accurate picture of your health than weight or BMI alone. Excess body fat — especially visceral fat around the abdomen — is associated with a higher risk of heart disease, type 2 diabetes, and other chronic conditions. Monitoring it helps you gauge the effectiveness of your diet and exercise program.
The most effective approach combines a moderate caloric deficit (eating less than you burn), regular aerobic exercise, and strength training to preserve lean muscle mass. High-protein diets help maintain muscle while losing fat. Consistency over time matters more than any short-term extreme approach.
Not all fat is harmful — essential fat is necessary for hormone production, organ protection, and nutrient absorption. The problem arises with excess storage fat, particularly visceral fat stored around internal organs. Maintaining body fat within a healthy range supports overall metabolic and hormonal health.
When you burn fat, triglycerides stored in fat cells are broken down into fatty acids and glycerol, which are metabolized for energy. The carbon dioxide produced is exhaled through the lungs, and water is excreted via sweat, urine, and breath. So most fat literally leaves the body through breathing.