Metallic nanoparticles are being researched and synthesized across the scientific disciplines for the unique properties that distinguish the nanoparticles from their bulk metal counterparts. One of those properties is an enhanced electromagnetic field that metallic nanoparticles display upon external excitation (e.g. laser), which, for specific cases, can be approximated using the guidance of existing models. A refined method will be needed to calculate the electromagnetic field for applications requiring complex systems of nanoparticles, such as those in optics and developing medical treatments. The basis of the project is a fundamental understanding of the electric fields of dipoles (the separation of opposite charges in a molecule or, in this case, a nanoparticle), starting from Coulomb’s law and Gauss’s law. By summing the external electric field and the electric field from the induced polarization of the nanoparticle, the homogeneous field inside the spherical metallic nanoparticle in relation to the dielectric permittivity of the nanoparticle metal (the material’s ability to transmit an electric field) was defined. Mathematica will be used to write a program that can compute electric fields based on input parameters including the dielectric permittivity of the nanoparticle, dielectric permittivity of the surrounding medium, laser wavelength, and nanoparticle radius. An objective of this project is to incorporate multiple nanoparticles in specific configurations.