Calculate FFMI transparently without unsupported natural-limit or drug-use claims.
Calculate with the FFMI Calculator
Enter the values below. Required fields are checked before results are shown.
FFMI Calculator results
How to use the FFMI Calculator
- Select the requested method and measurement system where available.
- Enter measurements using the units shown in each label.
- Select Calculate or press Enter.
- Review the method, source, assumptions, limitations, and visible safety note.
Worked example
At 80 kg, 175 cm, and 15% entered body fat, fat-free mass is 68 kg and FFMI is about 22.2.
Understanding the result
Body-fat estimation error directly changes FFMI.
Assumptions
- Entered body-fat percentage and measurements are representative.
Limitations
- Body-fat percentage is itself an estimate.
- FFMI does not diagnose body composition or infer drug use.
Sources and method references
- Fat-free mass index study by Kouri et al. (1995). Study population and historical context limit general interpretation.
Frequently asked questions
Why does body-fat measurement error matter?
The result is an educational estimate based on the selected method and entered assumptions. Individual measurements, needs, and outcomes vary.
Does CalculatorCheck store inputs from the FFMI Calculator?
No. The calculation runs locally in your browser; entries are not saved, transmitted, or added to the page URL.
Is this medical or dietary advice?
No. It does not diagnose, treat, or prescribe for any condition.