Understanding This Calculator
The US Navy method estimates body fat percentage from simple circumference measurements rather than expensive equipment like DEXA scans or hydrostatic weighing. Developed by Hodgdon and Beckett in 1984, it remains within 3-4% of more precise lab methods for most body types.
Consistent measurement technique matters: measure neck just below the larynx, waist at the navel, and hip (for women) at the widest point, keeping the tape snug but not compressing the skin.
- waist, neck, height circumferences in centimeters
- hip required for the women’s formula
| Category | Men | Women |
|---|---|---|
| Essential fat | 2-5% | 10-13% |
| Athletic | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Average | 18-24% | 25-31% |
| Obese | 25%+ | 32%+ |
Frequently Asked Questions
How accurate is the Navy method vs a DEXA scan?
Typically within 3-4 percentage points of DEXA for most body types, though accuracy decreases at the extremes of leanness or body fat. It’s best used to track trends over time rather than as an absolute number.
Why does the formula differ by gender?
Men and women store and distribute fat differently — women naturally carry more essential fat for reproductive function — so the regression equations were derived separately from sex-specific population data.