Body Fat Percentage Calculator

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Formula: US Navy Method: 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76 (men)

Body Fat Calculator

Body fat percentage is a more meaningful health metric than weight alone. The US Navy method estimates it using simple body measurements. Measurements are in inches — divide cm by 2.54 to convert (e.g., 86 cm waist = 33.9 in).

Conversion Formula

US Navy Method: 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76 (men)

The Navy formula uses logarithmic relationships between body circumferences and height to estimate fat percentage.

Step-by-Step Examples

Male, waist 34", neck 15", height 70" = ~16.5% (Fitness)

86.010 × log10(19) - 70.041 × log10(70) + 36.76

Frequently Asked Questions

How accurate is the Navy body fat method?

The US Navy method is accurate to within 1-3% for most people when measurements are taken correctly.

What is a healthy body fat percentage?

For men: 10-20% is healthy. For women: 18-28% is healthy. Athletes tend to be lower.

Where do I measure my waist?

Measure at the navel level for men, or at the narrowest point of the torso for women.

Can I enter measurements in centimeters?

This calculator uses inches. To convert from cm to inches, divide by 2.54. For example, a 86 cm waist = 33.9 in, a 38 cm neck = 15 in, and a height of 178 cm = 70 in.