A method and device are provided for determining an input voltage of a transformer of a local network station. The method includes measuring an input current of the transformer, an output current of the transformer, an output voltage of the transformer, and a phase angle between the output current and output voltage. The method also includes determining a translation ratio and an admittance of a cross-member of a p-equivalent circuit diagram of the transformer of the local network station using the measured input current, the measured output current, the measured output voltage and the phase angle between the output current and the output voltage. The method also includes determining the input voltage of the transformer of the local network station based on the determined translation ratio and the determined admittance of the cross-member of the p-equivalent circuit diagram.