Surface Plasmon Resonance (SPR) techniques are widely used in various chemical and biological sensors. This technique is also suitable for macromolecular interaction studies at solid/liquid interfaces. As it is being a reflectance technique, SPR response can be modeled using reflection equations. Reflection curves and estimated SPR response for uniformly coated and optically isotropic surfaces can be obtained by solving Fresnel reflection equations set via iteration. By using this simple iteration technique, substrate type, plasmon source type (metal interface) and thickness, as well as SPR curves and also, when approximate kinetics are known, sensor response can be predicted. In this paper, we tried to explain this iteration technique and gave simple routine sample (i.e., a modeling routine sample for Matlab (R)) for 3 layered system implementing a Kretschmann coupler.