Recently, nanostructured plasmonic antireflection coatings emerge as a solution to minimize reflection in solar cells over a wideband. However, metals have large light absorption coefficient, making this solution non-reliable for efficient large-scale production. On the other hand, all dielectric antireflection coatings are considered as promising alternative due to the lower losses and easier assembly, especially for third generation photovoltaics such as perovskite solar cells. Herein, we report a first principles methodology for selecting and comparing optimally nanostructured antirefiective coatings for enhancing the efficiency of perovskite solar cells based on Mie theory. The first part of the method includes studying absorption and scattering cross sections of five nanostructures and identifying the role of magnetic and electric dipoles. Accordingly, dimensions of each nanostructure that maximizes light coupling to the solar cell active layer was identified. The second part comprises the study of the coupling effect between closed nanostructures. Using three-dimensional finite element method optical and electrical model, periodicity and dimensions of the proposed nanostructures with the highest generated photocurrent were identified. The results showed 15% enhancement in short circuit current (J(sc)) over the entire wavelength band, and up to 27% in narrow band spectrum compared to planar perovskite solar cells.