Apparatus and method for estimating an engine output

There is provided a motor power estimator for estimating an engine output to a switching completion time point of a change in velocity of a vehicle. The engine power estimation device comprises a switch identifier unit, which is designed such that it detects the change in speed of the vehicle; an axle speed estimating unit, which is designed such that it calculates a target axle speed to the switching completion time point using an axle speed and a switching-time learning value upon detection of the change in speed of the vehicle; and an engine output estimation unit, which is designed such that it calculates a target motor power to the switching completion time point using the desired shaft speed and engine load information.