In recent years, inorganic perovskite solar cells have attracted increasing interest in the field of photovoltaics. This study focused on the optimization of these cells using CsPbCl3 as the absorber material through extensive simulations using SCAPS-1D software. In addition, first-principles calculations were performed using density functional theory (DFT) to explore the properties of CsPbCl3, such as its structure, energy band, total and partial density of states, and their optical properties. Different ETL layers, such as C60, ZnSe, PCBM, SnO2 and WS2, and an inorganic HTL composed of zinc-doped Cu2O (7%), were evaluated. The results showed that using SnO2 as the ETL yielded the best performance. The study also examined the impact of various critical parameters, such as the thickness and defect density of the absorber layer, donor doping density in this layer, series and shunt resistances, and operating temperatures, on the overall cell performance. The optimum device configuration, FTO/SnO2/CsPbCl3/Cu2O:Zn(7%)/Au, showed a PCE of 24.23%, FF of 88.45%, VOC of 1.567 V, and JSC of 17.48 mA/cm2. The results underline the crucial importance of CsPbCl3 for optical applications, particularly in solar energy conversion, highlighting the considerable potential of this material.