Flowmeter (1, 101) according to the vortex meter principle, comprising a measuring tube (2, 102) designed to conduct a fluid in the longitudinal direction of the measuring tube; a bluff body (4, 104), which is arranged in the measuring tube (2, 102), said bluff body serving to generate a Karman vortex street with a vortex frequency depending on the flow when a fluid flows through the measuring tube; a first pressure fluctuation measuring arrangement (12, 14, 112) designed to measure pressure fluctuations, which are caused by the vortex street, and designed to provide signals that are dependent on the pressure fluctuations; a second pressure fluctuation measuring arrangement (16, 18, 116) designed to measure pressure fluctuations, which are caused by the vortex street, and designed to provide signals that are dependent on the pressure fluctuations; wherein the first pressure fluctuation measuring arrangement (12, 14, 112) is spaced at a distance from the second pressure fluctuation measuring arrangement (16, 18, 116) in the longitudinal direction of the measuring tube; an evaluation unit (20, 120), which is configured to determine a vortex frequency using the signals of at least one of the pressure fluctuation measuring arrangements and to determine a flow measured value depending on the vortex frequency; characterized in that the evaluation unit (20, 120) is further configured to determine the current Reynolds number using the ratio of the amplitudes of the signals of the first pressure fluctuation measuring arrangement (12, 14, 112) and of the second pressure fluctuation measuring arrangement (16, 18, 116). a measuring tube (2, 102) designed to conduct a fluid in the longitudinal direction of the measuring tube; a bluff body (4, 104), which is arranged in the measuring tube (2, 102), said bluff body serving to generate a Karman vortex street with a vortex frequency depending on the flow when a fluid flows through the measuring tube; a first pressure fluctuation measuring arrangement (12, 14, 112) designed to measure pressure fluctuations, which are caused by the vortex street, and designed to provide signals that are dependent on the pressure fluctuations; a second pressure fluctuation measuring arrangement (16, 18, 116) designed to measure pressure fluctuations, which are caused by the vortex street, and designed to provide signals that are dependent on the pressure fluctuations; wherein the first pressure fluctuation measuring arrangement (12, 14, 112) is spaced at a distance from the second pressure fluctuation measuring arrangement (16, 18, 116) in the longitudinal direction of the measuring tube; an evaluation unit (20, 120), which is configured to determine a vortex frequency using the signals of at least one of the pressure fluctuation measuring arrangements and to determine a flow measured value depending on the vortex frequency; characterized in that the evaluation unit (20, 120) is further configured to determine the current Reynolds number using the ratio of the amplitudes of the signals of the first pressure fluctuation measuring arrangement (12, 14, 112) and of the second pressure fluctuation measuring arrangement (16, 18, 116).