This paper presents a 3D computational model we have created to enable easier and more accurate analysis of the wireless power transfer (WPT) based on the magnetic resonance coupling method (MRC). The model enables time-efficient analysis of practical issues in the design of an MRC WPT system, such as: the optimal size of the MRC system on the transmitting (Tx)- or receiving (Rx)- side, the effects that the distance between the Tx- and Rx- resonator, or between the excitation loop and the resonator, have on the power transfer efficiency and resonant frequency of the system, to mention a few. Experimental verification of the results has beed performed and showed a good agreement with the simulation.