Body Fat Calculator
Estimate your body fat percentage using the US Navy circumference method. Measure your neck, waist, and (for women) hip circumference, enter your height, and the calculator applies the Navy's logarithmic formula to produce a body fat estimate.
The result includes your estimated body fat percentage, fat mass, lean mass, and a fitness category (essential fat, athletes, fitness, average, or above average). Measurements can be entered in inches or centimeters, and weight in pounds or kilograms.
The US Navy method is a widely used field estimate — not as precise as DEXA or hydrostatic weighing, but practical and free. For the most accurate result, measure at the same time of day, use a flexible tape measure pulled snug but not compressing the skin, and take each measurement twice.
By The Paper Room Editorial Team — Calculator Tools
Frequently asked questions
How does the US Navy body fat formula work?▼
The formula uses logarithmic equations based on circumference measurements and height. For men: %BF = 86.01 x log10(waist - neck) - 70.041 x log10(height) + 36.76. For women: %BF = 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387. All measurements are in inches.
How accurate is the Navy method compared to DEXA?▼
The US Navy method is typically accurate to within 3-4 percentage points of DEXA for most people. It can be less accurate at very low or very high body fat levels, and tends to underestimate body fat in lean individuals. It is best used for tracking trends over time rather than as an absolute number.
Where exactly should I measure my waist and neck?▼
Measure your waist at the navel (belly button) level, and your neck just below the larynx (Adam's apple) sloping slightly downward to the front. For hips (women), measure at the widest point of the buttocks. Use a flexible tape pulled snug but not compressing the skin.
What is a healthy body fat percentage?▼
For men, essential fat is 2-5%, athletes 6-13%, fitness 14-17%, average 18-24%, and above average is 25%+. For women, essential fat is 10-13%, athletes 14-20%, fitness 21-24%, average 25-31%, and above average is 32%+. These ranges are general guidelines — ideal body composition depends on individual health factors.