Summary
US Navy circumference-based body-fat percentage estimate for educational comparison.
Calculation details
Use a level, flexible tape without compressing skin. Measure neck and waist consistently; the female equation also uses hip circumference. This estimate is not equivalent to a clinical body-composition assessment.
Formula
Male: 86.010 log10(waist-neck) - 70.041 log10(height) + 36.76. Female: 163.205 log10(waist+hip-neck) - 97.684 log10(height) - 78.387 (measurements in inches).
Worked example
Body fat worked example
The circumference relationship produces an approximate percentage.
How it works
Measure neck and waist (and hip for the female equation) with a level tape. Consistent landmarks matter more than chasing a single decimal.
Frequently asked questions
Is this a medical diagnosis?
No. It is an educational estimate and cannot diagnose a condition or replace individualized professional advice.
Why can my actual result differ?
Tape placement, posture, and hydration shift circumference-based estimates.
When is this calculator most useful?
Use it for educational body-composition comparison when DEXA or similar methods are unavailable.
How are results rounded?
The calculation retains full precision; centralized display formatting rounds only the visible result.