How to Calculate Body Fat Percentage
The U.S. Navy body fat formula uses circumference measurements to estimate body fat percentage. It is one of the most accessible methods, requiring only a tape measure. While not as precise as lab methods, it provides a useful estimate for tracking progress.
Body Fat Formula (Navy Method)
For Men:
Body Fat % = 495 / (1.0324 - 0.19077 x log10(waist - neck) + 0.15456 x log10(height)) - 450
For Women:
Body Fat % = 495 / (1.29579 - 0.35004 x log10(waist + hip - neck) + 0.22100 x log10(height)) - 450
How to Use This Calculator
- Select your gender
- Measure and enter your waist circumference in cm
- Measure and enter your neck circumference in cm
- Enter your height in cm
- For women: measure and enter your hip circumference in cm
Body Fat Categories
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2-5% | 10-13% |
| Athletes | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Average | 18-24% | 25-31% |
| Obese | 25%+ | 32%+ |
Body Fat Calculator FAQ
How does the Navy body fat method work?
The U.S. Navy method uses circumference measurements (waist, neck, and hip for women) along with height to estimate body fat percentage. It uses logarithmic formulas developed by the Naval Health Research Center and is accurate to within 3-4% of more precise methods.
What is a healthy body fat percentage?
For men: 6-13% (athletes), 14-17% (fitness), 18-24% (average), 25%+ (obese). For women: 14-20% (athletes), 21-24% (fitness), 25-31% (average), 32%+ (obese). Women naturally carry more essential body fat than men.
How do I measure my waist accurately?
Measure around your natural waistline, at the narrowest point of your torso (usually at or just above the belly button). Stand relaxed, do not suck in your stomach. Use a flexible tape measure and keep it snug but not compressing the skin.
Is this method accurate?
The Navy method is reasonably accurate for most people, typically within 3-4% of DEXA scan results. It may be less accurate for very lean or very obese individuals. For the most precise measurement, consider a DEXA scan or hydrostatic weighing.
Why is body fat percentage important?
Body fat percentage is a better indicator of health and fitness than weight alone. It distinguishes between fat mass and lean mass (muscle, bone, organs). Two people at the same weight can have very different body compositions and health profiles.