Navy Body Fat Calculator

The U.S. Navy method relies on logarithmic equations based on anthropometric measurements. Because body fat distribution differs between biological sexes, the formula utilizes distinct parameters for males and females. For males, the calculation uses height, neck girth, and waist girth at the navel. For females, it incorporates height, neck girth, natural waist girth, and hip girth at the widest point of the buttocks.

The mathematical models are expressed as: For males, Body Fat Percentage = 495 / (1.0324 - 0.19077 * log10(waist - neck) + 0.15456 * log10(height)) - 450. For females, Body Fat Percentage = 495 / (1.29579 - 0.35004 * log10(waist + hip - neck) + 0.22100 * log10(height)) - 450. These calculations evaluate how compactly mass is distributed relative to your stature.

Let us walk through an example for an adult male who is 72 inches tall (6 feet) with a neck circumference of 15 inches and a waist circumference of 34 inches. First, find the difference between waist and neck: 34 - 15 = 19. Next, calculate the base-10 logarithm of that difference: log10(19) is approximately 1.27875. Then, calculate the base-10 logarithm of his height: log10(72) is approximately 1.85733.

Substitute these values into the male denominator equation: 1.0324 - (0.19077 * 1.27875) + (0.15456 * 1.85733) yields 1.0324 - 0.24416 + 0.28706 = 1.07530. Finally, compute the total body fat percentage: (495 / 1.07530) - 450 = 460.337 - 450 = 10.33%. This individual has an estimated body fat of roughly 10.3%.

To ensure your tape measurements yield consistent and accurate results, keep the measuring tape level, parallel to the floor, and pulled firm without compressing the skin. For males, measure the neck just below the larynx and the waist horizontally at the navel level. For females, measure the neck just below the larynx, the natural waist at its narrowest point, and the hips at the maximum horizontal protrusion of the gluteal muscles. Take multiple readings and use the average for the best precision.