Adequate ductility is an important issue for fiber-reinforced polymer (FRP) reinforced concrete (RC) members because of the brittle behavior of FRP bars and concrete. FRP reinforcement in the tension side needs to be sufficient to prevent the brittle rupture of the FRP bars and attain the ultimate compressive strain in concrete in the compression side. Also, the maximum amount of FRP reinforcement should be within a certain limit to ensure the FRP-RC members that fail by crushing of concrete undergo a considerable deformation. In this study, analytical calculations were carried out to develop equations for limiting minimum and maximum FRP reinforcement ratios in the FRP-RC flexural members. Different arrangements of FRP reinforcing bars and different cross-sectional geometries were considered in this study. The minimum FRP reinforcement ratio can be selected either to prevent rupture of FRP bars or to control the crack width. Also, the maximum FRP reinforcement ratio can be selected to obtain a required deformability.