The resolution power of a seismic network is a crucial point both for scientific and legal reasons. Firstly it allow to understand whether an area is not affected by seismicity or we are just not able to detect it; consequently it is an important parameter when the possible seismicity is eventually associated with human activities. When subsoil exploitation is planned a certain minimum level of sensitivity to earthquake location is indeed usually required for the monitoring network to be installed. The sensitivity of a seismic network is its ability to detect or locate earthquakes. Here we present free downloadable and friendly software to define the sensitivity of a seismic network. Input to the program are the station positions, the seismic noise level of the area and the mean elastic properties of the area and the output is a grid with the minimum magnitude of earthquakes which are localizable or detectable at a certain depth.