SiC MOSFETs are key components in high-reliability, high-power-density electric drive inverters, making fast and accurate power loss calculations essential for device selection and thermal design. Current methods for determining the power loss of SiC MOSFETs using circuit simulation software have limitations, including complex debugging processes, time consumption, and incompatibility with devices lacking simulation models, which affects many domestic manufacturers. This paper proposes a fast calculation model for the power loss of SiC MOSFETs in inverters based on the power device datasheet. Simulations compared with PLECS software indicate that the maximum error in the total power loss calculated by the proposed method is approximately 5%. This level of accuracy provides valuable guidance for the preliminary screening and engineering application of SiC MOSFETs in electric drive inverters.