Provided is a motor driving device. The motor driving device includes a motor controller configured to output a first phase signal, a second phase signal, and a third phase signal on the basis of an angle signal, a gate driver configured to output a first phase control signal, a second phase control signal, and a third phase control signal to an external motor on the basis of the first phase signal, the second phase signal, and the third phase signal, respectively, a current sensor configured to detect a first phase current signal, a second phase current signal, and a third phase current signal from the first phase control signal, the second phase control signal, and the third phase control signal, and a sensorless calculation circuit configured to calculate a current calculation signal using the first phase current signal, the second phase current signal, and the third phase current signal, to calculate a voltage calculation signal using the first phase signal and the second phase signal, and to calculate the angle signal using the current calculation signal and the voltage calculation signal.