Social, behavioral, and health scientists frequently decompose changes or differences in outcome variables into components of change and assess their relative importance. Many Stata commands facilitate this exercise using unit-level data, notably by applying the Blinder–Oaxaca approach. However, none of the comparable user-written commands decompose changes or differences in aggregate data despite their availability and the widespread use of corresponding decomposition techniques. In this article, I present the user-written command rdecompose, which decomposes aggregate or cross-classified data based on Das Gupta's (1993, Standardization and Decomposition of Rates: A User’s Manual, Volume 1) approach, and demonstrate its application in multiple settings. This command extends the original method by allowing multiple factors and flexible functional specifications.