The article presents the original, mixed method of determining the range of individual settlement units within the existing administrative areas. Using GIS tools and raster graphics processing programs, it is possible to delimit urbanised clusters also in rural areas, for which no separate statistical and spatial data is collected. Additionally, thanks to the application of the presented method, it is possible – in some cases, to indicate the centrality of a given settlement unit, even in the absence of a spatially crystallised place, such as a square or main public park. The tool can be used on a subregional and local scale both to identify compact building structures in order to value them in terms of spatial order and to study their potential for transport-oriented development.