US Navy Method — How It Works
The US Navy body fat method was developed in the 1980s and requires only a tape measure. It uses circumference measurements at the neck, waist, and hips (females) along with height to estimate body density and then body fat percentage. Accuracy is within 3-4% of DEXA scans for most people.
For trainers: This method is ideal for regular client tracking because it requires no equipment beyond a tape measure. Take measurements at the same time of day, after clients have voided but before eating, for the most consistent results.
How accurate is the Navy body fat method?
Studies show accuracy within 3-4% for most adults compared to DEXA scans. It is less accurate for very lean individuals (below 8% for males, 15% for females) and for people with unusual fat distribution. For tracking progress over time, the consistency of the method matters more than absolute accuracy.
What is a healthy body fat percentage?
For men: 6-17% is athletic to fitness range, 18-25% is average. For women: 14-24% is athletic to fitness range, 25-31% is average. These ranges vary by age — older adults naturally carry slightly higher body fat while maintaining good health.
How often should I measure client body fat?
Monthly is ideal. Body fat changes slowly — weekly measurements are too frequent to show meaningful change and create anxiety. Monthly measurements allow enough time for genuine progress to be visible and give clients a clearer picture of their trend.