A method determines a fluid quantity relating to a fluid flowing in a measuring device. The measuring device has a measuring tube which receives the fluid, and first and second oscillation transducers. An excitation of a total wave, which is conducted through a wall of the measuring tube, by the first and/or second oscillation transducer, by wave components which are conducted in the wall being excited by the oscillation transducers in a plurality of excitation regions. These wave components are superposed to form the total wave. A distance between the centers of the excitation regions and the excitation frequency are selected such that an oscillation mode to be attenuated is quenched by destructive interference of the wave components in a propagation direction. Excitation of a compression oscillation of the fluid by the total wave occurs. Measurement data relating to the compression oscillation is used to determine the fluid quantity.