Soil pedogenic carbonates are precipitates of carbonate minerals, majorly calcite, that accumulate in soils in arid, temperate, and subtropical areas. They retain clues to their environment in their isotopic signature that make them important for paleoclimate reconstructions across subtropical to subpolar regions. However, we lack an exact understanding of pedogenic carbonate accumulation in subtropical and monsoonal regions, where heavy rainfall encourages leaching in the soil profile, yet soil carbonates are still observed. A clearer understanding of the process by which carbonates accumulate in the subtropics will aid the interpretation of isotopic data from past warmer and wetter periods. To better understand their formation in these soils, I used HYDRUS-1D, a numerical model that simulates soil processes, to track calcite accumulation over a five-year period under conditions resembling the environment of Myanmar, which today lies in the monsoonal domain. I tested various scenarios of rainfall, vegetation, soil type, and temperature to determine the control of these environmental factors on the depth, timing, and amount of calcite accumulation. Results show that as precipitation increases, the major effect on accumulation results from varying rainfall distribution and rooting depth. Most carbonate precipitation occurs during the dry season in winter and spring, indicating a clear seasonal bias in their isotopic record. This seasonal bias – commonly ignored in paleoenvironmental studies – should be considered in future work.