This study investigates the effect of externally bonded carbon fiber reinforced plastics (CFRP) laminates on the flexural capacity of reinforced concrete (RC) beams used in the strengthening and repair of damaged structures. The main goal of this study is the development of analytical capabilities to predict the flexural behavior of RC beams strengthened with CFRP. Reinforced concrete structures deteriorate over time due to environmental aging, fatigue, excessive loading, chemical attack, and other factors. Strengthening and rehabilitating these concrete structures by externally bonding carbon laminates is one of many economical engineering solutions. The final formulae of the required equations used to predict the flexural capacity, not only for rectangular sections but also for T beams, had been derived. A comparison between the flexural capacities calculated using the derived equation and those obtained from experimental tests, from different references, is made to check the validity of the proposed procedure. A good agreement between the calculated and the tested values is obtained.