Health & Fitness Calculators
Body Fat Calculator
Estimate body fat percentage with the US Navy circumference method using height, waist, neck, and (for women) hip measurements.
Quick guide
Choose your sex, then enter your height and your waist and neck measurements (plus hips for women) taken with a tape measure. The calculator estimates body fat percentage with the US Navy circumference method and shows the matching range.
Read the full explanationHow It Works
The US Navy method estimates body fat from body circumferences, which correlate with fat distribution. It needs only a tape measure and is reasonably accurate for most people.
Formula Used
Men: 86.01·log₁₀(waist − neck) − 70.041·log₁₀(height) + 36.76. Women: 163.205·log₁₀(waist + hip − neck) − 97.684·log₁₀(height) − 78.387 (inches).
Example Calculation
A 175 cm man with an 85 cm waist and 38 cm neck estimates to about 15% body fat — the “fitness” band.
Practical Use Cases
- Track body composition beyond what a scale shows.
- Set fat-loss goals instead of weight-loss goals.
- Monitor changes during a training program.