A motor control device is a motor control device which controls a spindle motor in a machine tool, and includes: a moving average filter which moving averages a torque command value or drive current value of the spindle motor for averaging time and generates averaged load information of the spindle motor; and an averaging time calculation unit which calculates, as the averaging time of the moving average filter, a first time of an integral multiple of a period of one rotation of the spindle driven by the spindle motor, or a second time of an integral multiple of a value arrived at by dividing the period of one rotation of the spindle by the number of cutting tooth of the tool.