A method for adaptive calibration of a fuel level indicator of a filling level of a liquid in a tank accompanying operations. A filling level of the liquid is detected with a sensor arrangement. A sensor signal of the arrangement is provided during a movement of the vehicle. In case that the course of the sensor signal is obtained in a respective defined time interval in which the sensor signal is provided several times, a constant value is assumed, an end stop is detected. The respective time intervals at which the end stops were detected and the respective associated constant values are stored. A minimum number of end stop is defined for the tank, and in the case that the minimum number of end stops is reached, a calibration phase is carried out.