Body Fat Percentage Calculator — US Navy Method

The US Navy method uses tape measurements of your neck, waist, and (for women) hips. Measure your neck at the narrowest point, waist at the navel, and hips at the widest point. Take measurements in the morning before eating. Use a flexible tape measure and keep it level. This calculator uses these measurements to estimate body fat percentage.

For men: Essential fat 2-5%, Athletes 6-13%, Fitness 14-17%, Average 18-24%, Obese 25%+. For women: Essential fat 10-13%, Athletes 14-20%, Fitness 21-24%, Average 25-31%, Obese 32%+. These ranges vary by age. This calculator shows your category based on your result.

The US Navy method estimates body fat using height and circumference measurements. It was developed by the US Military as a practical field method. For men, it uses neck and waist circumference. For women, it also uses hip circumference. The formula calculates a body density estimate, which is then converted to body fat percentage using the Siri equation.

The Navy method has an accuracy of +/- 3-4% compared to DEXA scans. It tends to slightly underestimate body fat in very lean individuals and overestimate in obese individuals. For most people, it provides a reasonable estimate that is useful for tracking progress over time. Consistency in measurement technique is more important than absolute accuracy.