This study investigated the impact of different stopping power (SP) tables on the range of therapeutic energy of carbon ions in water. Four SP tables were considered: those provided by ICRU reports 73 and 90, the stopping and range of ions in matter (SRIM) software, and the MSTAR program. The theoretical range calculations were performed based on a continuous slowing-down approximation for each SP table. Range calculations were performed using the Geant4 Monte Carlo simulation toolkit. In the Geant4 simulations, the Bragg curve was generated solely by varying the input SP table while keeping the other simulation parameters constant. The results demonstrate a significant variation in the range of carbon ions across different SP tables within the therapeutic energy range, with differences of up to 6 mm in both the theoretical and simulated calculations. Therefore, when simulating the Bragg curve of therapeutic energy carbon ions using Monte Carlo simulations, it is crucial to acknowledge the potential for several millimeters of variation in the Bragg peak position, depending on the chosen SP table. Furthermore, a careful comparison of the simulated Bragg peak positions with experimentally measured data across the entire therapeutic energy range is recommended.