DXA vs InBody: What a Muscle-Mass Percentile Actually Means

Find the right line on the report

DXA appendicular lean mass (ALM) adds lean mass from both arms and legs. Dividing by height squared reduces the expected size advantage of taller adults. Total skeletal muscle mass in pounds or kilograms is not interchangeable with ALMI.

If an InBody report includes SMI in kg/m², the calculator can accept it in BIA mode. Do not enter a total skeletal-muscle-mass value in that field.

Why the US selector includes race and ethnicity

The NHANES reference publication reports separate DXA curves for non-Hispanic White, non-Hispanic Black and Mexican American participants. That reflects the source table; it is not a claim that identity determines an individual's health.

Korean and Chinese options come from different studies, samples and DXA equipment. Their percentiles are context-specific references, not a country leaderboard.

BIA is useful, but it is not DXA

BIA estimates body composition from electrical impedance and is sensitive to hydration, recent food, exercise and manufacturer algorithms. Measure under similar conditions when following change over time.

Neither a percentile nor lean mass alone diagnoses sarcopenia. Clinical assessment also considers strength, physical performance, disease and the guideline used.

Common questions