Body Fat % Calculator (US Navy Method)
Estimate your body fat, lean mass, and fitness category using circumference measurements.
Your body fat % appears here
Enter your measurements and click Calculate.
US Navy Body Fat Formula
Men:
BF% = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76
Women:
BF% = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387
Step-by-Step Example
Male: Height 175 cm, Neck 38 cm, Waist 85 cm
log₁₀(85 − 38) = log₁₀(47) = 1.6721
log₁₀(175) = 2.2430
BF% = 86.010 × 1.6721 − 70.041 × 2.2430 + 36.76 = ≈ 18.4%
Category: Average
Frequently Asked Questions
How accurate is the US Navy method?
Research shows an error margin of ±3–4% compared to DEXA scanning. It is reliable for tracking changes over time, though less precise than laboratory methods.
Where exactly should I measure my waist?
Men: measure at the navel. Women: measure at the narrowest point of the torso, typically just above the belly button.
What is a healthy body fat range?
Men: 14–17% (fitness) or 18–24% (average). Women: 21–24% (fitness) or 25–31% (average). Elite athletes often fall in the 6–13% (men) or 14–20% (women) range.
Last reviewed: October 2024
Sources:
US Navy body composition assessment (OPNAVINST 6110.1J)· ACE body fat percentage norms
The US Navy method gives a population-level estimate. DEXA scanning is more accurate. Consult a healthcare professional.