A method for determining density and/or mass flow of a compressible medium with a measuring transducer of vibration-type having at least two oscillators, each including a pair of measuring tubes, wherein the pairs of measuring tubes are arranged for parallel flow, wherein the two oscillators have mutually independent oscillator oscillations with mutually differing eigenfrequencies for corresponding oscillation modes. The method includes steps of determining the values of the eigenfrequencies of at least two different oscillator oscillations, determining at least two preliminary density measured values based on the values of the eigenfrequencies, and determining a correction term for one of the preliminary density measured values and/or for a preliminary measured value of flow based on the preliminary density measured values and the values of the eigenfrequencies.