The present study describes the modeling and simulation of the effective strength of hybrid composites reinforced by carbon and steel fibers. The numerical simulations are performed within the framework of a finite element analysis. The macroscopic effective material properties are determined from microscopic properties using a homogenization and a representative volume element (RVE) approach. An elastic-plastic model is used to describe the mechanical behavior of the steel fibers and the epoxy resin, while the carbon fibers are modeled as a linear elastic material. The nonlinear stress-strain curves are determined under macroscopic longitudinal and transversal tensile as well as under shear loads. Moreover, 2D and 3D failure envelopes are computed. By using hexagonal-, square- and micrograph-based RVEs, the influences of fiber arrangements and different volume fractions of the carbon and steel fibers are investigated. Finally, the simulation results for tensile loads in fiber direction are compared with the experimental results of comparable topologies made of steel and carbon fiber reinforced plastics. The modeling and computational approach used in this study correlates with the experimentally determined, effective properties of hybrid composites in the tensile test.