Body Fat Calculator
Calculate body fat percentage using the U.S. Navy method with waist, neck, and height measurements.
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Body Fat Percentage
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Category —
Fat Mass —
Lean Mass —
How to Use This Calculator
Enter your gender, waist circumference, neck circumference, and height. Women should also enter hip measurement under "More options." For best results, measure in the morning before eating.
Formula
Male: BF% = 495 / (1.0324 - 0.19077 × log10(waist - neck) + 0.15456 × log10(height)) - 450
Female: BF% = 495 / (1.29579 - 0.35004 × log10(waist + hip - neck) + 0.22100 × log10(height)) - 450
Female: BF% = 495 / (1.29579 - 0.35004 × log10(waist + hip - neck) + 0.22100 × log10(height)) - 450
Example
Example: A male with 34" waist, 15" neck, 70" height: BF% = 495 / (1.0324 - 0.19077 × log10(48.26) + 0.15456 × log10(177.8)) - 450 ≈ 17.7% (Average/Fitness range).
Frequently Asked Questions
- The Navy method is accurate within 1-3% for most people. It is less accurate for very lean or very overweight individuals. DEXA scans are the gold standard.
- For men: 14-17% is fitness level, 18-24% is average. For women: 21-24% is fitness, 25-31% is average. Athletes may be lower.
- Measure at the navel (belly button) level for men. For women, measure at the narrowest point of the waist.
- The Navy formula uses different equations for men and women. The female formula requires waist, hip, neck, and height for accuracy.