The US Navy Body Fat Method
The US Navy method estimates body fat percentage using circumference measurements of the waist, neck, and (for women) hips, along with height. It was developed by Hodgdon and Beckett at the Naval Health Research Center and is used by the US military for fitness assessments. While not as precise as DEXA scans or hydrostatic weighing, it provides a reliable estimate with no special equipment.
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
For the most accurate results, take measurements first thing in the morning on bare skin. Measure your waist at the navel (not at the narrowest point), your neck just below the larynx, and for women, hips at the widest point. Use a flexible tape measure and keep it snug but not compressing the skin. Take each measurement twice and average them.
Frequently Asked Questions
How accurate is the US Navy body fat method?
The US Navy method is accurate to within about 3-4% of DEXA scan results for most people. It's most accurate for individuals with average body compositions and may be less precise for very lean or very overweight individuals.
Where exactly should I measure my waist?
Measure your waist horizontally at the level of your navel (belly button). Stand relaxed, don't suck in your stomach, and take the measurement at the end of a normal exhalation.
Why do women need a hip measurement?
Women's body fat distribution differs significantly from men's, with more fat stored in the hips and thighs. The hip measurement improves accuracy for the female formula by accounting for this difference.
What is essential fat?
Essential fat is the minimum amount of fat needed for basic physiological functions. For men it's 2-5% and for women 10-13%. Going below these levels can cause serious health problems including hormone disruption and organ damage.
How often should I measure body fat?
Measure every 2-4 weeks if you're actively working on body composition changes. Always measure at the same time of day under the same conditions for consistent tracking.