Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
Body fat
17.4%
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter units.
- 2Enter sex.
- 3Enter height.
- 4Enter neck circumference.
- 5Enter waist circumference.
- 6Enter hip (women only).
- 7Read your body fat on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Uses the U.S. Navy circumference method (neck, waist, hips for women) to estimate body fat percent.