Body fat calculator.
Measure your neck and waist, and hips if you use the women's equation, enter your height, and see an estimated body fat percentage you can track over time.
These tools are free to use without an account.
Estimated body fat
16.5%About 13.2 kg fat and 66.8 kg lean mass.
This is a fitness estimate from tape measurements, not a medical measurement or a medical device. It commonly differs from DEXA, bioimpedance and other methods by several percentage points, and it is sensitive to where and how tightly you measure. It is most useful for watching your own trend with the same technique.
Fitness estimates for adults 18 and over, not medical or dietary advice. Results are informational and are not reviewed by a certified personal trainer.
How the tape-measure method works
The US Navy method estimates body fat from circumference measurements and height using a logarithmic equation: neck and waist for the men's equation, neck, waist and hips for the women's. It is the same US Navy method the One Fitness Hub Body tab uses when you log a check-in with tape measurements. Measure in the morning, relaxed, with the tape snug but not pressing into the skin, and take each measurement two or three times and use the average.
Where to measure, and how far to trust it
Measure the neck just below the larynx, the waist at the level of the navel for men and at the narrowest point for women, and the hips at the widest point. The method is easy and needs nothing but a tape, but it is an estimate: it can differ from DEXA or other lab methods by several percentage points and is sensitive to small changes in where the tape sits. Use it to watch a trend with the same technique, not to decide a single number.
Fitness estimates for adults 18 and over, not medical or dietary advice. Results are informational and are not reviewed by a certified personal trainer. Calculations stay in your browser. Typed measurements are not sent or saved.
Common questions.
How accurate is a tape-measure body fat estimate?
It is a rough estimate that commonly differs from DEXA and other lab methods by several percentage points. Where you place the tape changes the answer, so it is best used to follow your own trend with the same technique.
Where do I measure my waist?
For the men's equation, measure at the level of the navel. For the women's equation, measure at the narrowest part of the waist. Stand relaxed, breathe out normally and keep the tape level and snug without pressing into the skin.
Does the app use this same method?
Yes. The One Fitness Hub Body tab estimates body fat from the neck, waist and hip measurements in a check-in with the same US Navy method, and always labels it as an estimate.
Embed this calculator on your website
Copy this HTML. The link credits One Fitness Hub and opens the full explanation.
Keep your progress in one place.
Track training, food and body progress with One Fitness Hub.