In this paper we compute models for relativistic white dwarfs in the presence of strong magnetic fields. These models possibly contribute to superluminous SNIa. With an assumed axisymmetric and poloidal magnetic field, we study the possibility of the existence of super-Chandrasekhar magnetized white dwarfs by solving numerically the Einstein-Maxwell equations, by means of a pseudospectral method. We obtain a self-consistent rotating and nonrotating magnetized white dwarf model. According to our results, a maximum mass for a static magnetized white dwarf is $2.13{\mathrm{M}}_{\odot }$ in the Newtonian case, and $2.09{\mathrm{M}}_{\odot }$ when taking into account general relativistic effects. Furthermore, we present results for rotating magnetized white dwarfs. The maximum magnetic field strength reached at the center of white dwarfs is of the order of ${10}^{15}\mathrm{G}$ in the static case, whereas for magnetized white dwarfs, rotating with the Keplerian angular velocity, it is of the order of ${10}^{14}\mathrm{G}$.