This paper presents CRMag PLUS, a sophisticated simulation software designed to accurately predict the Magnetic Flux Density (MFD) of overhead electrical lines. A standout feature of CRMag PLUS is its ability to intricately model both the catenary shape of power lines and the real terrain profile beneath. This dual modeling capability enables the software to simulate electromagnetic fields with unprecedented precision, crucial for assessing the MFD’s impact at any point on the ground. CRMag PLUS leverages advanced algorithms to represent the complex physical characteristics of electrical installations, particularly high-voltage (HV) lines. By integrating the catenary equation for cable modeling and detailed terrain data, the software provides a realistic depiction of the electromagnetic field distribution around power lines. This level of detail is essential for accurately predicting MFD values in varying topographical conditions. The utility of CRMag PLUS is illustrated through a detailed case study, which showcases the software’s application in evaluating MFD levels under a HV line. The results obtained demonstrate not only the software’s accuracy but also its importance in ensuring compliance with health and safety standards for electromagnetic field exposure.