A method is used for determining an operating point of a compressor that includes at least one impeller, compressor blades attached to the impeller, a housing and at least two sensors. The method includes calculating a deflection of the compressor blades. An operating point and a surge margin with respect to a surge limit are determined based on the calculating of the deflection by measuring passage times of the compressor blades at a sensor. A signal that is representative of a rotation speed is determined and is associated with the compressor impeller. In a learning or adaptation mode, compressor blade-specific, state-induced and position-induced deviations from an ideal state are determined using compressor blade-specific passage times that are measured and compared with ideal passage times. In a working mode, compressor blade-specific passage times are measured and the compressor blade-specific passage times are corrected using the determined state-induced and position-induced deviations.