A method for planning a radiocommunications network includes computing cell coverage in turn including dividing a region around a radio base station into a number of large environment pixels, dividing each large environment pixel into a number of small environment pixels, and, for each target small environment pixel, computing a second quantity indicative of the coverage within the target small environment pixel, wherein each second quantity is computed for the respective target small environment pixel as a function of a mixed environment profile describing the environment between the radio base station and the target small environment pixel along a propagation path of a radioelectric signal radiating out from the radio base station and passing through the target small environment pixel, wherein the mixed environment profile describes the environment within small environment pixels close to the radio base station and the target small environment pixel, and within large environment pixels along the remaining stretch of the radioelectric signal propagation path.