the invention relates to a method and an apparatus for measuring a rotational speed , in particular a rotational speed of a wheel of a motor vehicle , by means of a speed sensor , wherein the speed sensor produces an output signal characterizing the actual rotational speed and wherein the output signal of the speed sensor is sampled and further processed in accordance with sampled values thus obtained . for an — in hardware terms — simple realization , according to the invention it is provided that the output signal is sampled at a predetermined sampling rate over at least one measuring cycle , that in each case the amplitude of sampled values obtained in the measuring cycle is determined and that from the rate of occurrence of sampled values of an amplitude lying within a predetermined amplitude range at least one signal level occurring during the measuring cycle in the output signal is determined .