Navy Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy circumference method — the same formula used for military body composition standards.
Calculated instantly in your browser — nothing is sent to or stored on our servers.
How This Is Calculated
The U.S. Navy method estimates body fat percentage from a few simple tape measurements instead of calipers or scans. It was developed for military body composition assessments and remains widely used for its simplicity.
The Formula
Men: Body Fat% = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76. Women: Body Fat% = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387.
Measuring Correctly
Measure your neck just below the larynx, your waist at the navel, and (for women) your hips at their widest point — keep the tape snug but not compressing the skin.
Accurate within a few percentage points for most people.
This method estimates body fat and is not a medical measurement. Consistent measurement technique matters more than any single reading.
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