What Is the Body Fat Calculator
This tool estimates body fat percentage from height, neck, waist, and hip measurements using the U.S. Navy circumference formula. It also returns category ranges and can compute fat mass and lean mass when weight is provided.
How to Use
- Select gender. Hip measurement is required for women.
- Enter height, neck, and waist in centimeters.
- Optionally enter weight to get fat mass and lean mass.
- Results update automatically once required inputs are complete.
Measurement Tips
- Measure neck below the Adam's apple while standing relaxed.
- Measure waist at navel level without holding your breath.
- For women, measure hip at the widest point and keep the tape level.
- Morning fasted measurements are more stable; take 2-3 readings and average them.
Formula Notes
- Male:
495 / (1.0324 - 0.19077 log10(waist - neck) + 0.15456 log10(height)) - 450 - Female:
495 / (1.29579 - 0.35004 log10(waist + hip - neck) + 0.22100 log10(height)) - 450 - The formula is applied directly to centimeter inputs, so no manual unit conversion is needed.
Use Cases
- Track body composition during fat-loss or fitness phases.
- Adjust diet and training plans in weight management.
- Monitor circumference changes in daily health routines.
Notes
- Circumference readings are sensitive to posture and breathing; take 2-3 readings and average them.
- Waist must be greater than neck. For women, waist plus hip must also be greater than neck.
- Results are for reference and do not replace medical diagnosis.