A method for estimating power consumption of a motor includes steps of: determining an error voltage for a terminal voltage of each of multiple phases of the motor, the terminal voltage being supplied from an inverter to the motor; generating a compensation terminal voltage for each of the multiple phases of the motor by applying the error voltage to a prediction value of the terminal voltage that is derived in a preset manner during operation of the motor; and calculating power consumption of the motor by using the compensation terminal voltage and a current value obtained by detecting a current that flows in each of the multiple phases of the motor.