Navy body fat calculator

Estimate adult body-fat percentage with the legacy circumference equations commonly called the Navy method.

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Height (inches)

Equation

More inputs and assumptions

Neck circumference (inches)

Abdomen at navel (male) or natural waist (female), inches

Hip circumference (female equation only), inches

Answer

…

Estimate adult body-fat percentage with the legacy circumference equations commonly called the Navy method.

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Precision and calculation record

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Formula and assumptions

Male: 86.010 log10(abdomen minus neck) - 70.041 log10(height) + 36.76. Female: 163.205 log10(waist plus hip minus neck) - 97.684 log10(height) - 78.387. All measurements are inches. Use the named measurement sites; no military rounding protocol is applied. This is an adult estimate, not a measurement, diagnosis or current Navy eligibility assessment. Values outside 0-100% are rejected rather than clipped. Changes in this estimate do not establish changes in body composition.

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Updated 2026-09-29

Using Navy body fat calculator

Estimate adult body-fat percentage with the legacy circumference equations commonly called the Navy method.

Next: FFMI calculator

Next: Calculate BMI

A worked example

For height (inches) = 70, equation = Male circumference equation, neck circumference (inches) = 16, abdomen at navel (male) or natural waist (female), inches = 36, hip circumference (female equation only), inches = 40, estimated body fat (%) = 19.429078.

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