A position estimation unit of a motor control apparatus includes a counter electromotive voltage estimation unit configured to estimate a counter electromotive voltage generated in a motor based on generated voltage and current of the motor, and an arc tangent calculation unit configured to perform an arc tangent calculation using coordinate data on a two-dimensional plane based on the estimated counter electromotive voltage to calculate an angle of deviation. The arc tangent calculation unit includes a rotation calculation unit configured to repeatedly perform a rotation calculation of coordinate data on a fundamental wave and a harmonic; a rotation direction judgment unit configured to judge a rotation direction of a subsequent rotation calculation based on a result of the rotation calculation of the rotation calculation unit; and a deviation angle calculation unit configured to calculate a total of rotation angles obtained as a result of the rotation calculation.