Body Fat Percentage Calculator
This body fat calculator uses the U.S. Navy circumference (tape) method to estimate your body fat percentage from a few simple measurements. Add your weight to also see estimated fat mass and lean mass.
How the Navy method works
The U.S. Navy circumference method estimates body-fat percentage from height and a small set of tape measurements. Men use waist and neck; women also use hip circumference. The calculation is designed as a practical field estimate rather than a lab measurement.
Men: 495 ÷ (1.0324 − 0.19077·log₁₀(waist − neck) + 0.15456·log₁₀(height)) − 450
Women: 495 ÷ (1.29579 − 0.35004·log₁₀(waist + hip − neck) + 0.22100·log₁₀(height)) − 450
How to take each measurement
- Neck: measure just below the larynx with the tape snug but not tight.
- Waist: men measure at the navel; women measure at the narrowest part of the torso.
- Hip (women): measure around the widest part of the hips and buttocks.
- Repeat measurements and use a consistent tape position for better trend tracking.
Body fat percentage categories
| Category | Men | Women |
|---|---|---|
| Essential | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Accuracy & alternatives
Tape-based body-fat estimates can differ from DEXA, hydrostatic weighing and other lab methods. They are most useful when measurements are taken the same way over time. Compare the result with other measures such as BMI, waist-to-hip ratio and lean body mass rather than relying on one number alone.
Frequently asked questions
How accurate is the Navy body fat method?
- It is a field estimate and can differ from laboratory methods by several percentage points; consistent technique matters most for tracking trends.
Where do I measure my waist and neck?
- Measure the neck just below the larynx. Men measure the waist at the navel; women measure at the narrowest part and also measure the hips at their widest point.
What is a healthy body fat percentage?
- Healthy ranges vary with age, sex and context. The category table above is a general reference rather than an individual diagnosis.
Why does the women's formula need a hip measurement?
- The formula includes hip circumference because typical fat-distribution patterns differ between men and women.
Body fat % vs BMI — which is better?
- They measure different things. Body-fat percentage estimates composition, while BMI is a weight-for-height screening measure.
Disclaimer. This is a circumference-based estimate for healthy adults, not a clinical body-composition measurement or medical advice.