How to get an accurate measurement
1
Neck Measurement
Measure just below the Adam's apple for men, or the narrowest part for women. Keep the tape level.
2
Waist & Hips
Measure at the navel for men. Women should measure the narrowest part of the waist and the widest part of the hips.
3
Input & Analyze
Enter your values into the calculator. We'll use the U.S. Navy formula to provide your estimate instantly.
The Science of Circumference
Developed by the U.S. Navy Health Research Center, this method is one of the most reliable ways to estimate body fat without expensive equipment like DXA scans or hydrostatic weighing. It uses simple tape measurements to calculate body density with surprising accuracy.
Method
U.S. Navy Standard
Accuracy
+/- 3-4% Variance
Body Fat Classifications (ACE)
Men
Essential Fat
2 - 5%
Athletes
6 - 13%
Fitness
14 - 17%
Average
18 - 24%
Obese
25%+
Women
Essential Fat
10 - 13%
Athletes
14 - 20%
Fitness
21 - 24%
Average
25 - 31%
Obese
32%+
Expert Q&A
When should I measure?
For consistency, measure in the morning after waking up and using the bathroom, but before eating. Your body water content changes throughout the day, which can affect measurements slightly.
How accurate is this method?
While no formula is perfect, the Navy method is widely considered the most accurate "tape measurement" method. It typically stays within 3-4% of expensive DEXA scan results, making it an excellent tool for tracking progress over time.