The EarthCAD software package consists of two units that exchange information with each other. The first unit consists of a part of the software package responsible for the calculation of complex grounding systems in homogeneous soil. This part also includes the equivalence of two-layers with the corresponding homogeneous soil. The second unit consists of a part of the software package developed for the calculation of the distribution of single-pole short-circuit current in passive parts of power lines, and the reduction factor of transmission lines and cable lines. The engine part of this software package was developed by Prof.dr.sc. Ivan Medic.