Calculate your body fat percentage using the US Navy method. Free online body fat calculator with formula, examples, and FAQ.
Body fat percentage is the proportion of fat to total body weight. The US Navy method uses simple circumference measurements to estimate body fat percentage. While not as precise as DEXA scans or hydrostatic weighing, it provides a reliable estimate that is widely used in military, fitness, and health settings.
Male: 86.010 × log₁₀(waist - neck) - 70.041 × log₁₀(height) + 36.76
Female: 163.205 × log₁₀(waist + hip - neck) - 97.684 × log₁₀(height) - 78.387The US Navy body fat formula was developed from regression analysis of anthropometric measurements against hydrostatic weighing data. It uses the relationship between circumference measurements and body density to estimate fat percentage. The formula accounts for the fact that fat tends to accumulate around the waist (and hips for females).
| Input | Output |
|---|---|
| Male, waist: 85 cm, neck: 38 cm, height: 175 cm | Body Fat: ~17.6% (Fitness) |
| Female, waist: 75 cm, neck: 34 cm, hip: 95 cm, height: 165 cm | Body Fat: ~24.2% (Fitness) |
| Male, waist: 100 cm, neck: 40 cm, height: 180 cm | Body Fat: ~24.5% (Average) |