What is the Body Fat Calculator?
Estimate body fat percentage with the US Navy tape-measure method.
Enter sex, height, neck, waist, hip (women only) and weight and the Body Fat Calculator returns body fat, fat mass and lean mass. Results update as you type, and nothing you enter leaves your device.
How it is calculated
This is a general estimate for adults and not medical advice. Talk to a doctor or dietitian about your own health.
How to use it
- Choose sex.
- Enter height in cm.
- Enter neck in cm.
- Enter waist in cm.
- Enter hip (women only) in cm.
- Enter weight in kg.
- Read body fat in the results panel. It updates as you type.
- Change any value to compare scenarios, or use Share to send the result as a link.
Worked example
Common questions
What formula does the Body Fat Calculator use?
It uses: Men: 495 ÷ (1.0324 − 0.19077 × log10(waist − neck) + 0.15456 × log10(height)) − 450; Women: 495 ÷ (1.29579 − 0.35004 × log10(waist + hip − neck) + 0.221 × log10(height)) − 450.
What do I need to use the Body Fat Calculator?
You need sex, height, neck, waist, hip (women only) and weight. Sensible starting values are filled in so you can see how it works straight away.
Is the Body Fat Calculator free, and is my data stored?
It is free with no sign-up. The calculation runs in your browser, so the values you enter are not sent to or stored on our server.