Method for determining the angular position of the rotor of a synchronous motor fed by an inverter, wherein the inverter is actuated by signal electronics comprising a controller unit, wherein a stator current, I_S, is detected, wherein the synchronous motor has a stator winding that is fed by a three-phase voltage, i.e. a stator voltage, that is provided by the inverter in such a way that the detected stator current, I_S, is controlled towards a predetermined target stator current, I_Soll, by the controller unit, wherein the target stator current, I_Soll, is predetermined by a first adjustment angle in relation to the stator winding, wherein the stator flux, Y, is determined from the time curve of the stator voltage and of the detected values of the stator current, I_S, wherein the angular position, i.e. an angle value, a, is determined from the determined stator flux, Y, and from a flux-value dependency that is dependent on the stator current, wherein the flux-value dependency has a flux value as a function of the rotor angle and of the stator current, I_S, wherein each characteristic curve has a respective flux component as a function of the stator current, I_S, such that each interpolation point has the value of the respective component in the stator current, I_S, currently being detected, characterised in that the function is an interpolation function that is interpolated between interpolation points, wherein each interpolation function is a second-order function and/or an ellipse, wherein a first characteristic curve representing the components Y_d of the flux in the d-direction, i.e. in a first direction of a rotor-based coordinate system, is ascertained, wherein a second characteristic curve representing the components Y_-d of the flux in the opposite direction to the d-direction, i.e. in the opposite direction to the first direction of the rotor-based coordinate system, is ascertained, wherein a third characteristic curve representing the components Y_q of the flux n the q-direction, i.e. in the direction perpendicular to the first direction of the rotor-based coordinate system, is ascertained, wherein each interpolation point is ascertained from the value of the stator current, I_S, by means of a respective characteristic curve. wherein the inverter is actuated by signal electronics comprising a controller unit, wherein a stator current, I_S, is detected, wherein the synchronous motor has a stator winding that is fed by a three-phase voltage, i.e. a stator voltage, that is provided by the inverter in such a way that the detected stator current, I_S, is controlled towards a predetermined target stator current, I_Soll, by the controller unit, wherein the target stator current, I_Soll, is predetermined by a first adjustment angle in relation to the stator winding, wherein the stator flux, Y, is determined from the time curve of the stator voltage and of the detected values of the stator current, I_S, wherein the angular position, i.e. an angle value, a, is determined from the determined stator flux, Y, and from a flux-value dependency that is dependent on the stator current, wherein the flux-value dependency has a flux value as a function of the rotor angle and of the stator current, I_S, wherein each characteristic curve has a respective flux component as a function of the stator current, I_S, such that each interpolation point has the value of the respective component in the stator current, I_S, currently being detected, characterised in that the function is an interpolation function that is interpolated between interpolation points, wherein each interpolation function is a second-order function and/or an ellipse, wherein a first characteristic curve representing the components Y_d of the flux in the d-direction, i.e. in a first direction of a rotor-based coordinate system, is ascertained, wherein a second characteristic curve representing the components Y_-d of the flux in the opposite direction to the d-direction, i.e. in the opposite direction to the first direction of the rotor-based coordinate system, is ascertained, wherein a third characteristic curve representing the components Y_q of the flux n the q-direction, i.e. in the direction perpendicular to the first direction of the rotor-based coordinate system, is ascertained, wherein each interpolation point is ascertained from the value of the stator current, I_S, by means of a respective characteristic curve.