Body Fat Calculator

How the US Navy Body Fat Formula Works

The US Navy method estimates body fat percentage using circumference measurements of the neck, waist, and (for women) hips, along with height. It was developed by Hodgdon and Beckett at the Naval Health Research Center and is used by the US military for fitness assessments.

For men: %BF = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76

For women: %BF = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387

Body Fat Percentage Categories

• Essential Fat: Men 2–5% | Women 10–13%
• Athletes: Men 6–13% | Women 14–20%
• Fitness: Men 14–17% | Women 21–24%
• Average: Men 18–24% | Women 25–31%
• Obese: Men 25%+ | Women 32%+

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