A method for operating a synchronous machine having a rotor, comprising the following features: the synchronous machine is modelled, with respect to the rotor, as a two-phase system with a direct-axis current and a quadrature-axis current, rotor losses of the synchronous machine, which rotor losses occur in the rotor, are numerically described by an evaluation function of the first direct-axis current, of the quadrature-axis current and of a specified rotation speed of the synchronous machine, and, on the basis of the evaluation function, the direct-axis current and the second quadrature-axis current are controlled for the specified rotation speed and a required torque in such a way that the synchronous machine outputs the required torque and the rotor losses are low and a corresponding synchronous machine, a corresponding computer program and a corresponding storage medium.