In this article, computational parameters of magnetic shielding effectiveness are analyzed, and their effects on magnetic shielding effectiveness are presented for enclosure designers of electronic devices, providing valuable knowledge for electromagnetic interference and compatibility. First, conventional analytical equivalent circuit models and common powerful simulators are compared to improve familiarity results at 0 to 1 GHz. As a novelty frequency range is enhanced 0 to 3 GHz interval, then all possible parameters are examined in simulators to determine right comments. FEKO results are preferred for issue to others capable of both time and frequency domain computations. Especially, size of enclosure, size, shape, configuration and number of apertures, and probe position are impressive parameters that effect magnetic shielding effectiveness. Obtained results of these parametric approaches are explained with acceptable reasons.