A method for determining residual coupling of an inductive, conductivity sensor, in which the conductivity sensor is surrounded by a measured medium and an equivalent impedance of the medium is calibrated with a variable compensation impedance. The variable compensation impedance and the equivalent impedance of the medium act on a measuring coil of the conductivity sensor with a phase shift of 180°. In order to be able to perform a measuring of the residual coupling with a high accuracy of measurement at any time during operation of the conductivity sensor, the variable compensation impedance is varied until an output voltage of the measuring coil of the conductivity sensor assumes a minimum voltage; wherein the minimum voltage corresponds to the residual coupling of the inductive, conductivity sensor.