This paper deals with investigation of size-independent fracture energy (G_F) of concrete. The study involves numerical modeling of three point bend concrete beams that are geometrically similar having constant length to depth ratio with varying notch to depth ratios. RILEM fracture energy (G_f) values evaluated numerically and experimentally are found to be in reasonable agreement. G_F is estimated from developed relationship of fracture energy release rate and through bilinear model by G_f values. G_f values have been utilized to develop a simple methodology for estimation of G_F. Comparative analysis of G_F from three different methodologies has been carried out.