How FFMI is calculated
Fat-free mass is bodyweight minus estimated fat mass. Raw FFMI divides fat-free mass by height squared; the Kouri adjustment normalizes the value toward a height of 1.80 m.
K Y S E R O / T O O L S
Estimate fat-free mass relative to height
Calculate raw and height-normalized FFMI without unsupported natural-limit labels.
Body-fat measurement error carries directly into this result. Treat the value as an estimate, not a diagnosis.
What FFMI cannot establish
FFMI inherits the error of the entered body-fat estimate. It cannot diagnose health, prove drug use or establish a universal natural muscularity limit.