Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy Method based on simple body measurements.
Body Fat Percentage
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Category
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Fat Mass
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Lean Mass
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How to Use the Body Fat Calculator
- Select your gender: The formula differs for men and women (women require a hip measurement).
- Choose your unit system: Select Metric (cm) or Imperial (in).
- Enter your measurements: Measure your height, neck, waist, and hip (women only) at the widest/narrowest points.
- Optionally enter weight: Adding your weight will also show fat mass and lean mass in kg or lb.
- View your results: Body fat percentage, category, and mass breakdown appear instantly.
Navy Method Formula
The U.S. Navy body fat formula uses circumference measurements:
- Men: BF% = 495 / (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450
- Women: BF% = 495 / (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.22100 × log10(height)) − 450
All measurements should be in centimeters for the formula above (the calculator handles conversion automatically).
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%+ |
Frequently Asked Questions
How accurate is the Navy Method?
The Navy Method is generally accurate within 1-3% of more advanced methods like DEXA scans. It is widely used because it only requires a tape measure. For the most accurate results, measure at the same time of day and use consistent landmarks on your body.
Where should I measure my waist?
For men, measure at the navel (belly button) level. For women, measure at the narrowest point of your waist, typically just above the navel. Stand relaxed and breathe normally — do not suck in your stomach.
What is a healthy body fat percentage?
For men, a healthy range is typically 10-20%. For women, it is 18-28%. Athletes and very active individuals may be lower. Essential fat (the minimum needed for health) is around 2-5% for men and 10-13% for women.