Army Body Fat Calculator

The US Army body fat percentage method uses circumference measurements (neck, waist, hips for women) instead of underwater weighing or DEXA scans. It’s designed for field use — fast, consistent, and requiring only a flexible tape measure.

Formulas:

For Men: Body Fat % = 86.010 × log₁₀(Waist − Neck) − 70.041 × log₁₀(Height) + 36.76

For Women: Body Fat % = 163.205 × log₁₀(Waist + Hip − Neck) − 97.684 × log₁₀(Height) − 78.387

All measurements in inches.

How to measure correctly:

• Neck: Measure just below the larynx (Adam’s apple), perpendicular to the long axis. Round UP to nearest 0.5 inch.
• Waist (men): At the navel, against the skin. Round DOWN to nearest 0.5 inch.
• Waist (women): At the narrowest point. Round DOWN to nearest 0.5 inch.
• Hip (women): At the widest point, parallel to the floor. Round DOWN to nearest 0.5 inch.
• Height: Measure without shoes, feet together. Round DOWN to nearest 0.5 inch.

US Army body fat standards (maximum allowed):

Worked example (Male): Height: 70 inches | Waist: 34 inches | Neck: 15.5 inches

Body Fat = 86.010 × log₁₀(34 − 15.5) − 70.041 × log₁₀(70) + 36.76 = 86.010 × log₁₀(18.5) − 70.041 × log₁₀(70) + 36.76 = 86.010 × 1.2672 − 70.041 × 1.8451 + 36.76 = 108.99 − 129.19 + 36.76 = 16.56%

At age 28, this male passes the Army standard (maximum 24%).

Accuracy note: This method has a margin of error of ±3–4 percentage points compared to DEXA scanning. It tends to slightly overestimate body fat in muscular individuals.