A radio signal path design tool that allows radio link propagation path profiling or path-loss measurement where the link partner antenna towers are located in a proposed fixed location on the earth's surface, but are extendable a certain distance in any direction from the fixed location. The design tool can be used to compute a radio link path profile at the proposed tower location, while still correctly representing terrain variations in a variable path extension distance on either side of the radio link. To correctly represent terrain variations across the depicted portion of the earth's surface, the tool computes and applies a modified earth-bulge factor or k-factor. The variable extension distance on either side of the radio link allows for latitudinal and/or longitudinal variations in antenna tower placement, greatly facilitating the identification of appropriate positions of antenna towers during the wireless link design phase.