Body fat calculator
Enter sex, height, neck and waist, plus hips for the women's equation. The page shows body fat, fat mass, lean mass and the ACE category.
- US Navy method
- Free, no sign-up
This is a standard estimate to plan with. It is general information, and your doctor is the right person for medical advice.
These are standard formulas for planning. Your doctor, dietitian or pharmacist is the right person for medical advice.
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How to use it
- Choose centimetres or inches.
- Enter height, neck, waist and, for women, hips, plus weight.
- Read body fat, the category, and fat and lean mass.
The US Navy circumference method
The page uses the Navy percent equations. For men: 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76. For women: 163.205 × log10(waist + hips − neck) − 97.684 × log10(height) − 78.387. Measure in inches, or enter centimetres and the page converts them. Height is without shoes. The neck is just below the larynx, the waist is at the navel for men and at the narrowest point for women, and the hips are at the widest point.
The category uses adult ranges published by the American Council on Exercise: athletes, fitness, average and above. Fat mass is body fat percent times weight, and lean mass is the rest. Measure at the same time of day when you compare weeks. These are standard formulas for planning. Your doctor, dietitian or pharmacist is the right person for medical advice.
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Questions
How does the US Navy body fat method work?
A tape measure at the neck, waist and hips, with height, estimates body fat. The men's equation uses waist and neck. The women's equation adds hips.
Where should the tape sit?
Neck: just under the larynx. Men: waist at the navel. Women: waist at the narrowest point and hips at the widest point. Keep the tape level and snug.
What do the ACE categories mean?
They are adult labels: essential fat, athletes, fitness, average and obese, with different cut points for men and women. They describe the percentage, and a clinician reads it for you.
Can I enter centimetres?
Yes. Choose centimetres and kilograms. The page converts to inches before the Navy equation, so the result matches an inch entry of the same body.
Why pair this with weight?
The percentage becomes kilograms or pounds of fat and of everything else. That split is easier to track than the percentage alone.