How it's calculated
Men: BF% = 86.010·log₁₀(waist − neck) − 70.041·log₁₀(height) + 36.76; Women: 163.205·log₁₀(waist + hip − neck) − 97.684·log₁₀(height) − 78.387
Hodgdon–Beckett (US Navy) tape method. waist, neck, hip, height measured in inches; log₁₀ = base-10 logarithm. Pass/fail compared to the selected service's age- and sex-based cap.
Common questions
What measurements does the Navy method need?
For men, neck and waist plus height. For women, neck, waist, hips, and height.
How accurate is the tape method?
It is a reasonable estimate within a few percent for most people, but less precise than methods like DEXA scans.