This paper presents the development of two procedures to determine induction motor efficiency according to the IEC 60034 2-1 standard. In first instance, with the motor at environment temperature, the efficiency is calculate by the direct measurement method (method 2-1-1A). Then keeping the motor at full load, it is operating until the thermal equilibrium, in this moment the efficiency is determinate by direct method. Finally, the method of separation of losses is implemented (method 2-1-1B), which requires more analysis in order to obtaining the different types of losses according its nature.