Army Body Fat Calculator
Estimate body-fat percentage from tape measurements using the US Army/Navy circumference method.
How it works
BF% = 495 ÷ (1.0324 − 0.19077·log₁₀(waist − neck) + 0.15456·log₁₀(height)) − 450 (men)
The Army’s circumference (tape) method is the same math as the US Navy body-fat formula: girth measurements stand in for body density. Men use neck and waist; women add the hip. Measure with a flexible tape held snug but not compressing, take each site twice and average, and results land within about 3–4% of lab methods.
Worked example
A man 69 inches tall with a 34-inch waist and 15-inch neck: BF ≈ 495 ÷ (1.0324 − 0.19077 × log₁₀(19) + 0.15456 × log₁₀(69)) − 450 ≈ 11.5%.
Frequently asked questions
Does this decide if I pass the Army standard?
No. Pass/fail thresholds depend on age and sex and the Army revises both the limits and the measurement method over time — this page estimates body fat only. Check current regulations for official standards.
Where do I measure the waist?
For the male formula, measure at the navel; for the female formula, at the narrowest point. Keep the tape level and breathe out normally before reading.
Why does the tape method sometimes read high?
It assumes an average fat distribution. A thick, muscular waist or an unusually large neck can throw it off, so pair it with how you look and perform.
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General educational estimate, not medical advice. Talk to a doctor for anything about your health.