BMI can't tell fat from muscle, but a simple tape measure can get you a reasonable body fat estimate using the U.S. Navy method — the same approach the U.S. military uses for body composition standards. Enter your measurements to get an instant estimate.
How to use the body fat calculator tool
- 1
Measure yourself
Neck just below the larynx, waist at the navel, and (for women) hips at the widest point — all in centimeters.
- 2
Enter your measurements
Along with your height and gender.
- 3
Read your estimate
Your estimated body fat percentage appears instantly.
Common use cases
Track body composition over time
Re-measure periodically to see body fat trends alongside weight.
Get a better health picture than BMI alone
Body fat percentage accounts for what BMI can't — how much of your weight is fat versus muscle.
Set a body composition goal
Use the estimate as a starting baseline for a fitness goal.
Frequently asked questions
It's a reasonably reliable estimate for most people (typically within a few percentage points of more precise methods like DEXA scans), which is why it's still used by the U.S. military for body composition standards.