Calculate lean mass, FFMI, and height-normalised FFMI from weight, height, and body-fat percent.
| Lean mass | – |
| FFMI | – |
| Normalised FFMI | – |
Use this calculator for LBM = weight × (1 − fat%/100), FFMI = LBM / height_m², and normalised FFMI = FFMI + 6.1 × (1.8 − height_m). Gym folklore treats about 25 as a natural ceiling for men; that is not a lab fact.
Weight can be entered in kilograms (kg) or pounds (lb). Height can be entered in centimetres (cm) or inches (in). Lean mass follows the weight unit.
Weight: Scale weight, in kg or lb.
Height: Standing height, in cm or in.
Body fat: Body-fat percent from a tape, scan, or estimate.
Lean mass: Fat-free mass.
FFMI: Fat-free mass index in kg/m².
Normalised FFMI: Height-adjusted FFMI.
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