Fat free mass

How is lean body mass estimated?

Uses LBM ≈ weight × (1 − body_fat% / 100) with body fat entered as a percent (0–99). Fat mass is treated as proportional; measurement error in BF% dominates uncertainty.

Does the decimal separator matter?

This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.