Skeletal Muscle Mass (SMM) Calculator Skeletal Muscle Index Calculator Metric (kg / cm) Imperial (lb / ft+in) Age ❔ Sex MaleFemale Height (cm) Weight (kg) Height (ft) Height (in) Weight (lb) Calculate Your Results Skeletal Muscle Mass: kg Skeletal Muscle Index (SMI): kg·m-2 Cut‑points from Janssen et al. 2000 (DXA‑validated SMI). SMI computed from Lee et al. (2000) SMM estimate; typical error ± 3 kg.