🏋️ US Navy Circumference Method
Body Fat Percentage Calculator
Estimate your body fat percentage using the US Navy formula from simple tape measurements.
lbs
Body Fat %
18.4%
Category
Fitness
Fat Mass
33.1 lbs
Lean Body Mass
146.9 lbs
Body Fat Classification Chart (ACE Guidelines):
| Category | Women | Men |
|---|---|---|
| Essential Fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Average | 25–31% | 18–24% |
| Obese | 32%+ | 25%+ |
US Navy Body Fat Formula
The US Department of Defense uses circumference-based equations published in the NAVPERS 6110.1 fitness standards:
- Men: $BF\% = 86.010 \times \log_{10}(\text{waist} - \text{neck}) - 70.041 \times \log_{10}(\text{height}) + 36.76$
- Women: $BF\% = 163.205 \times \log_{10}(\text{waist} + \text{hip} - \text{neck}) - 97.684 \times \log_{10}(\text{height}) - 78.387$
All measurements in inches (or converted from centimetres). This method correlates within ±3–4% of hydrostatic weighing and DEXA scans for most healthy adults.