A method for evaluating discrete measurement data sequences of an ultrasonic flow measuring device having a recording frequency and ultrasound signal, includes determining time position or height of a maximum of a sinusoidal profile of a time sequence of evaluation values, determined as part of a measurement data sequence or cross-correlation of two sequences recorded at different positions of the device by determining a maximum evaluation value of the time sequence and evaluation values thereof adjacent thereto. Initial values, including an initial maximum value and time, are determined by quadratic fit of evaluation values. Output values including output time describing the position or output height describing the height of the maximum are determined by a determination relationship setting output values in relation with initial values and a calculation quantity formed from selected evaluation values for known recording frequency and known signal frequency and based on a known sinusoidal profile.