A method for ascertaining volume- or mass-flow of a medium in a pipeline, or measuring tube, of radius (r) via a sound entrainment method, wherein ultrasonic measuring signals are transmitted and/or received along a plurality of defined sound paths (m). During a calibration phase, successive, different flow profiles (v(r)) of a measured medium are established in the pipeline, or in the measuring tube, and wherein, for each flow profile (v(r)), a defined volume flow, or a defined mass flow, is ascertained, wherein, on the basis of measured values (vx(r1) . . . vx(rm)) ascertained in the separate measuring paths (m), each flow profile (v(r)) established in the pipeline, or in the measuring tube, is described by a characteristic parameter set (a1, . . . , an with nεN) and wherein, for each flow profile (V(r)), on the basis of the defined volume- or mass-flow and on the basis of the measured volume- or mass-flow, a flow-profile-dependent correction factor MF(a1, . . . , an) is calculated, and wherein, subsequently in measurement operation, a volume- or mass-flow ascertained via the parameter set (a1, . . . , an, with nεN) is corrected with the flow-profile-dependent correction factor MF(a1, . . . , an) determined during the calibration phase.