Body Fat Calculator
Two validated estimates side by side: the Navy circumference method and the simpler BMI-based formula.
Body fat (Navy method)
15.1%
- BMI-based estimate
- 22.6%
- Fat mass (Navy)
- 27.1 lb
- Lean mass (Navy)
- 152.9 lb
Navy method needs waist > neck. Tape at the narrowest point, level all around.
How the Body Fat Calculator works
The calculation follows the standard method used across the US — no shortcuts, no hidden assumptions. Here is exactly what happens behind the scenes:
Frequently Asked Questions
How does the Body Fat Calculator work?
Enter your numbers above and results update instantly using standard formulas, computed entirely on your device.
Is the Body Fat Calculator free to use?
Yes — completely free with no signup required, and it works on phones, tablets, and desktops.
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