Fat-Free Mass Index (FFMI)

Normalises your lean mass for height — BMI’s counterpart for muscle.

How this is worked out

Kouri et al. (1995), height-normalised. It builds on your body-fat figure and inherits that estimate’s error. A ceiling of about 25 for drug-free trained men is often quoted; that is an observation from a small sample, not a personal limit.

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