Glass fiber reinforced polymer (GFRP) rebar is a rod made of composite material. It has the potential to replace steel rebar as reinforcement in concrete structures. Despite being anti-corrosive, strong, durable and cheaper in longer run, its adaptation in India is being hindered due to lack of Indian design guidelines. In the current research, GFRP rebars reinforced concrete (RC) beams and steel rebars RC beams have been designed as per ACI 440.1R-15 and IS: 456 (2000) respectively. GFRP RC beams were designed as under reinforced, balanced and over reinforced section beams. Total 16 beams have been casted and tested and an experimental and analytical comparative study has been done on its flexural capacity, deflection and design philosophy. The experimental results indicated that over reinforced design shall be preferred as compared to under reinforced and balanced designs for GFRP RC beams. Over reinforced GFRP RC beams successfully achieved strength as well as serviceability criteria.