Navy Body Fat Calculator

Estimating Body Composition the Navy Way

The U.S. Navy Body Fat Calculator estimates your body fat percentage using a circumference-based method. It's a simple and convenient way to track body composition without expensive equipment. This method is used by the Navy as part of its Physical Fitness Assessment (PFA).

The Navy Formula Explained

This method uses gender, height, and circumference measurements to estimate body fat percentage.

• For Males: %Fat = 86.010 * log10(Waist - Neck) - 70.041 * log10(Height) + 36.76
• For Females: %Fat = 163.205 * log10(Waist + Hip - Neck) - 97.684 * log10(Height) - 78.387 (Note: All measurements are in inches for these specific equations).

How to Use the Calculator

1. Select Gender: Choose between male and female.
2. Enter Measurements: Input your height, waist, and neck measurements in inches. For females, also include your hip measurement.
3. Calculate: The tool will display your estimated body fat percentage.

Real-World Example

A female is 65 inches tall, with a 28-inch waist, a 13-inch neck, and 38-inch hips.

• Calculation: 163.205 * log10(28 + 38 - 13) - 97.684 * log10(65) - 78.387 ≈ 24.8%
• Her estimated body fat percentage is 24.8%.

Frequently Asked Questions (FAQ)

• How accurate is this method? It's a reasonable estimation for general tracking, with an accuracy often cited as ±3-4% compared to clinical methods. It's most useful for tracking changes over time rather than for a single, definitive measurement.
• Where exactly should I measure?
  • Neck: Just below the larynx (Adam's apple).
  • Waist: For men, at the navel. For women, at the narrowest point between the navel and the bottom of the ribs.
  • Hips (Women only): At the widest point of the hips or buttocks.
• What are the Navy's body fat standards? The standards vary by age group. Generally, for males, the limit is around 22-26%, and for females, it's around 33-36%.