Body Fat Calculator
Estimate your body fat percentage from neck, waist, and hip measurements. Choose US, EU, or International units.
About this calculator
What is body fat percentage?
Body fat percentage estimates the proportion of your total body weight that is fat tissue. Unlike BMI, circumference-based methods account for body shape and are often used in fitness and military settings.
This calculator uses the U.S. Navy circumference method, which measures neck, waist, and (for women) hip with a flexible tape. Results are estimates — DEXA scan or hydrostatic weighing are more precise.
How to measure correctly
Neck: measure just below the larynx, tape horizontal.
Waist: measure at navel level for men; at the narrowest point for women (Navy protocol uses abdomen at navel for men).
Hip (women): measure at the widest point of the hips/buttocks.
Do not compress the skin. Take measurements in the morning for consistency.
Reference tables & standards
ACE body fat percentage categories — men
Source: American Council on Exercise (ACE)| Category | Body fat % |
|---|---|
| Essential fat | 2 – 5% |
| Athletes | 6 – 13% |
| Fitness | 14 – 17% |
| Average | 18 – 24% |
| Obese | 25%+ |
ACE body fat percentage categories — women
Source: American Council on Exercise (ACE)| Category | Body fat % |
|---|---|
| Essential fat | 10 – 13% |
| Athletes | 14 – 20% |
| Fitness | 21 – 24% |
| Average | 25 – 31% |
| Obese | 32%+ |
U.S. Department of Defense (Navy) method
Source: U.S. Navy / DoD body composition program
| Input | Used for |
|---|---|
| Height | Scales the circumference relationship |
| Neck | Reduces estimated fat from circumference |
| Waist | Abdominal adiposity indicator |
| Hip (women) | Additional shape variable in female formula |
Maximum allowable body fat standards for U.S. military service differ by age and sex; this tool does not evaluate military fitness compliance.
These calculators provide estimates for educational purposes only. They are not a substitute for professional medical advice, diagnosis, or treatment.