A method for determining the fill level of a medium involves continuous wave radar measurement and a corresponding fill level measuring device. A coded transmit signal is emitted by a transmitter, reflected at the medium, and received by a receiver as a reflection signal. The reflection signal and a signal derived from the transmit signal are subjected to a correlation analysis, and a correlation outcome results. A control and evaluation unit determines the time offset of the correlated signals with the correlation outcome, and uses it to determine the fill level of the medium. The reflection signal and the derived signal are mixed with the analog mixer into a mixer output signal that is sampled and quantized to a digital mixer output signal. The correlator has a digital integrator with which a sequence of digital mixer output signals is digitally integrated into the correlation outcome.