Why use this calculator
Body fat percentage is a more accurate indicator of health and fitness than weight or BMI alone. The US Navy method provides a reasonable estimate using simple body measurements.
How to use it
Enter your gender, waist circumference (at navel), neck circumference, and height. Females also enter hip circumference. Measure at the widest points.
The formula
US Navy Method. Males: 86.010 × log10(waist - neck) - 70.041 × log10(height) + 36.76. Females: 163.205 × log10(waist + hip - neck) - 97.684 × log10(height) - 78.387.
Worked examples
Male, 34" waist, 15.5" neck, 5'10" tall
Approximately 16.5% body fat — Fitness category
When people use it
- Fitness progress tracking
- Health assessment
- Body composition analysis
Tips
- Measure consistently at the same time of day
- Use a flexible tape measure pulled snug but not tight
- This is an estimate — DEXA scans are the gold standard for accuracy
Questions people ask
- What is a healthy body fat percentage?
- For men: 10-20% is fit, 14-24% is average. For women: 18-28% is fit, 25-31% is average. Athletes may be lower. Essential fat minimums are ~3% for men and ~12% for women.