Body Fat Percentage Calculator
Estimate your body fat percentage from simple tape measurements with the US Navy method.
- No upload
- Browser-based
- Free
- No signup
Body fat
0%
—
- Fat mass—
- Lean mass—
US Navy circumference method. Runs entirely in your browser — an estimate, not medical advice.
Calculated in your browser.
How to use Body Fat Calculator
- Choose metric or imperial and your sex.
- Enter your height, neck and waist (and hip for women).
- Optionally add your weight for fat and lean mass.
- Read your estimated body fat percentage and category.
Common use cases
- Fitness tracking.
- Cutting or bulking.
- Health awareness.
Tips
- Measure at the same time of day and in the same way each time for consistent trends.
- Body fat, not just weight, tells you whether you're losing fat or muscle.
Troubleshooting
Frequently asked questions
- How does the US Navy method work?
- It estimates body fat from tape measurements — neck and waist for men, plus hip for women — together with your height, using the official Navy circumference formula. Add your weight to also see fat mass and lean mass.
- How accurate is it?
- For most people it's within a few percent of more expensive methods when you measure carefully. It's an estimate for tracking trends, not a clinical measurement.
- How should I measure?
- Use a flexible tape, snug but not compressing. Measure the neck below the larynx, the waist at the navel (men) or the narrowest point (women), and the hips at the widest point (women).
- Is anything I enter uploaded?
- No. Everything runs entirely in your browser — nothing you enter is uploaded, stored or shared, and no signup is needed.