Army Body Fat Calculator

1. Select your gender. The Army uses different formulas and standards for male and female soldiers.
2. Choose your unit. Enter measurements in inches or centimeters, whichever you prefer. Tape measurements for Army purposes are officially recorded in inches.
3. Enter your age. The maximum allowable body fat percentage increases with age, so your age group determines whether you pass.
4. Measure your height. Stand straight without shoes. Measure to the nearest half-inch or centimeter.
5. Measure neck circumference. Measure below the larynx (Adam's apple), perpendicular to the long axis of the neck. Keep the tape snug but not compressing the skin.
6. Measure waist circumference. For men: at the navel level. For women: at the narrowest point of the abdomen (typically just above the navel).
7. Women also measure hip circumference. Measure at the largest point of the buttocks, parallel to the floor.

The U.S. Army uses a circumference-based body fat estimation method defined in Army Regulation 600-9. It uses neck, waist, hip (women), and height measurements rather than skinfold calipers.

Male formula:

%BF = 86.010 × log10(waist - neck)
     - 70.041 × log10(height)
     + 36.76

Female formula:

%BF = 163.205 × log10(waist + hip - neck)
     - 97.684 × log10(height)
     - 78.387

All measurements are in inches for these formulas. The calculator converts cm to inches automatically.

Worked example (male, inches): Height = 70 in, Neck = 15 in, Waist = 32 in

%BF = 86.010 × log10(32 - 15) - 70.041 × log10(70) + 36.76
    = 86.010 × log10(17) - 70.041 × log10(70) + 36.76
    = 86.010 × 1.2304 - 70.041 × 1.8451 + 36.76
    = 105.82 - 129.24 + 36.76
    = 13.3%

This formula has an average error of about 3 to 4 percentage points compared to DEXA scan measurements, which is typical for circumference-based methods.