Body Fat Percentage Calculator
Calculate your body fat percentage using three validated methods — the US Navy formula, Jackson-Pollock 3-site skinfold, or BMI-based estimation. Get fat mass, lean mass, and fitness classification.
📏 Calculate Body Fat Percentage
Skinfold measurements require calipers. Measure at the standard anatomical sites described in the Jackson-Pollock protocol.
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Body Fat Percentage — Methods & Classification
Body fat percentage is a more meaningful measure of body composition than weight or BMI alone, as it distinguishes between fat mass and lean mass (muscle, bone, organs, water). This calculator offers three validated methods, each with different requirements and accuracy levels.
US Navy Method
Developed by the US Navy for large-scale assessment, this formula uses circumference measurements (waist, neck, and hip for females) to estimate body fat. It is practical, requires no special equipment, and has good accuracy for average populations (standard error ±3–4%).
- Males: BF% = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76
- Females: BF% = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387
Jackson-Pollock 3-Site Skinfold Method
The Jackson-Pollock method uses skinfold caliper measurements at three standardised anatomical sites. It is more accurate than circumference methods (standard error ±2.5–3.5%) and is widely used in fitness and clinical settings. Body density is calculated first, then converted to body fat % using the Siri equation.
BMI-Based Estimation (Deurenberg 1991)
When no measurements beyond height, weight, age, and sex are available, the Deurenberg formula estimates body fat from BMI. It is the least accurate method (standard error ±5%) but useful for quick screening. For more accurate results, use the Navy or Jackson-Pollock method.
Body Fat Classification
- Essential fat: Men 2–5% / Women 10–13% — minimum for survival
- Athletic: Men 6–13% / Women 14–20%
- Fitness: Men 14–17% / Women 21–24%
- Average: Men 18–24% / Women 25–31%
- Obese: Men ≥25% / Women ≥32%
Combine body fat % with our calorie calculator and BMR calculator for a complete body composition assessment. For fitness training guidance, see our Fitness & Wellness tools.
⚠️ All body fat estimation methods have inherent error ranges. For clinical body composition assessment, DEXA scan or hydrostatic weighing provides the highest accuracy.