This study investigates the possibility of simulating the behavior of reinforced concrete (RC) beams subjected to flexure using a simplified elasto-isotropic damage. The phenomenological damage concept was used to evaluate stress-induced damage. The influence of the damage on elastic stiffness was used to evaluate mechanical performance with respect to material degradation. RC beams damaged in flexure with 40 %, 60 %, 75 %, and 90 % of ultimate flexural loading were modeled using the COMSOL Multi-physics finite element package to simulate mechanical performance of RC concrete beams. The proposed elasto-damage model predicted the ultimate load of the RC beams with 1 % estimated error. The proposed model showed similar ability to predict the axial strain for the reinforcement steel as the maximum strain in tensile reinforcement. The accuracy of these results were compared with other constitutive models for concrete such as elasto-plastic damage model reported in literature. The outcome of this research paper provides engineers with a simplified approach for analyzing the behavior of RC beams subjected to flexural loading using elasto-damage model.