US Navy Formula
Women: BF% = 163.205×log(waist+hip−neck) − 97.684×log(height) − 78.387
(All measurements in centimeters; log = log₁₀)
Body Fat Categories
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
How to Measure Correctly
- Waist: Measure at the narrowest point (for men) or at the navel level
- Neck: Measure just below the larynx (Adam's apple), sloping slightly downward
- Hip (women only): Measure at the widest point around the hips and buttocks
- Measure in the morning, relaxed, not sucking in your stomach
- Take 3 measurements and average them for accuracy
Frequently Asked Questions
How accurate is the US Navy method?
The US Navy method is accurate to within ±3–4% of DEXA scan results for most people. It is significantly more accurate than BMI-based estimates (which can be off by 5–8%). The gold standard is DEXA scanning or hydrostatic weighing, but the tape measure method is a practical alternative for regular tracking.
What body fat percentage is healthy?
For men, 10–20% is generally considered healthy; 15–18% is a typical fit range. For women, 20–30% is healthy; 22–26% is a typical fit range. Very low body fat (below 5% men, below 13% women) can cause hormonal disruption. Some body fat is essential for organ protection, hormone production, and vitamin absorption.
Is body fat percentage better than BMI?
Body fat percentage is a better health indicator than BMI because BMI doesn't distinguish between fat and muscle. A muscular athlete may have a high BMI but very low body fat. However, BMI is quicker to calculate and still useful for population-level health screening when direct body fat measurement isn't available.