Entropy generation calculation for the reversed cycle Carnot machine is presented. It is based on recent developments using the Direct Method and the Finite Speed Thermodynamics. The Direct Method consists in analyzing any irreversible cycle, step by step, on each process, by writing the corresponding equation of the First Law of Thermodynamics for Finite Speed Processes and integrating it on the whole cycle. The First Law expression for Finite Speed Processes includes principal sources of internal irreversibility and it is used here to develop equations that relate properties for each irreversible process that may occur with finite speed in the reversed cycle Carnot machine. This paper includes expressions for calculating the internal entropy generation as a function of the finite speed of the process and also as a function of other parameters such as the temperature of the gas, compression/expansion ratio, and mass flow rate and gas properties for the adiabatic finite speed processes of reversed Carnot cycle machines. An example is presented to illustrate how these expressions can be used to validate the internal entropy generation rate evaluation based on proposed equations in the literature for a real operating refrigeration machine for which experimental data are available. For this purpose an equivalent reversed Carnot cycle is considered instead of the real cycle. It results from experimental data using appropriate approximations for evaporator and condenser processes.