The Navy Method Formulas
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
Women: %BF = 163.205×log10(waist+hip−neck) − 97.684×log10(height) − 78.387
Common Mistakes
- Measuring waist at the wrong spot — measure at the navel, not the narrowest point, for consistency with the formula.
- Sucking in your stomach while measuring — this dramatically skews the result; measure naturally.
- Comparing Navy method results directly to DEXA scan results — tape-measure methods are estimates with a margin of error of a few percentage points, not lab-grade precision.
Quick Reference
Healthy ranges: Men 10-20%, Women 18-28%, depending on age and fitness level.
Frequently Asked Questions
Why does the formula use logarithms?
The relationship between body circumference measurements and actual body density isn't linear, so the Navy method uses logarithmic scaling to better approximate the true fat percentage from simple tape measurements.
Does this formula work for all body types?
It's reasonably accurate for most average body types but can be less precise for very lean athletes or individuals with atypical fat distribution.
