The present disclosure relates to a method for determining the delivery rate of a liquid conveying device, in particular a concrete pump, wherein on the basis of measured values concerning the pressure of the liquid the number of the pump strokes of the concrete conveying device is determined, in particular substantially calculated, by series-connection of a plurality of filters with adaptive filter length and variable detection limits. Furthermore, the present disclosure relates to a liquid conveying device and to a construction vehicle with a liquid conveying device.