How to measure
- Height: without shoes.
- Neck: just below the Adam’s apple, tape sloping slightly down to the front.
- Waist: men at the navel; women at the narrowest point. Relax and don’t suck in.
- Hips (women): around the widest part of the buttocks.
Measure on bare skin, keep the tape level and snug but not compressing, and take each measurement two or three times.
The U.S. Navy formula
Developed by the U.S. Naval Health Research Center, the method estimates body fat from circumference measurements and height. Studies typically find it within about 3–4 percentage points of lab methods like DEXA for most people — good for tracking changes over time with the same tape and technique.
Body fat categories
| 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%+ |
Source: American Council on Exercise (ACE).
Body fat vs BMI
BMI uses only height and weight, so a muscular person can be labelled “overweight”. Body fat percentage shows what that weight is made of. Waist size on its own is also a useful health marker: a waist over 40 in (102 cm) for men or 35 in (88 cm) for women is linked with higher health risks. To change body composition, combine strength training with a suitable calorie intake — estimate yours with the calorie calculator.
Frequently asked questions
What is a healthy body fat percentage?
For many adults, about 14–24% for men and 21–31% for women (ACE fitness and average ranges).
How accurate is the Navy body fat method?
Usually within a few percentage points of lab tests when measurements are taken carefully.
Where do I measure my waist?
Men at the navel; women at the narrowest point of the waist.
Is body fat percentage better than BMI?
It’s more informative about body composition, especially for muscular people.