This page contains some useful formulas for radio "link budget" calculations. Note that the calculations are based on assumptions of certain circumstances and should only be used as a guideline for radio network design. In reality, many factors can have an impact on the radio link. Planning of a radio network is usually done by first simulating the network in a desktop propagation study using a professional software package. The results are then verified by performing a field survey.
However, the calculators on this page can show whether the radio link has an acceptable fade margin or, if not, how much antenna gain needs to be added, or if repeaters have to be used.