FFMI Calculator
Calculate fat-free mass index and height-normalized FFMI from height, weight and body-fat percentage.
Enter or adjust the values above, then calculate.
FFMI: fat-Free Mass Index & Normalized FFMI
Calculate fat-free mass index and height-normalized FFMI from height, weight and body-fat percentage.
Inputs this tool uses
- Height
- Weight
- Body fat
What you get
Fat-free mass index with optional height normalization.
How to use the FFMI Calculator
- Enter height, weight, body fat.
- Select any method, activity level or option shown on this page, then choose Calculate.
- Read the main result together with the supporting values, method, assumptions and limitations below before using the estimate.
How this calculation works
FFMI divides fat-free mass by height squared. A height-normalized comparison is shown separately.
Example calculation
The sample values loaded into the calculator produce 19.9. This example exists to show how the output is structured; replace the sample values with your own inputs for your calculation.
Assumptions and limitations
- Anthropometric formulas are estimates and can differ from direct clinical measurements.
- Results are educational screening/reference values and do not diagnose health conditions.
Sources and review status
Source set last verified 2026-09-25. No clinician review is claimed unless a real named reviewer is displayed.
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