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FFMI Calculator (Fat-Free Mass Index)
Calculate your Fat-Free Mass Index (FFMI) to measure muscular development relative to height.
Your total body weight in kilograms
Your current body fat percentage
Your height in centimetres
Results
Lean Body Mass68.0 kg
FFMI21.5
Normalized FFMI (for height)21.6
What is it?
Fat-Free Mass Index (FFMI) is a measure of muscular development relative to height, similar to BMI but using lean mass instead of total weight.
How to use
Enter your body weight, body fat percentage, and height. The calculator will compute your lean body mass and FFMI score.
Example scenario
A 80 kg male at 15% body fat and 178 cm has a lean mass of 68 kg and an FFMI of ~21.4 — well within natural range.
Pro tip
A normalized FFMI above 25 is generally considered the natural ceiling. Values above 26 may suggest anabolic enhancement.