A virtual T-section may be formed and considered in the design process of reinforced concrete (RC) beam, when a part of the topping slab and the projecting beam acts as a single unit in resisting the flexural positive moment. Based on an extensive overview on the controlling parameters adopted by different design standards for calculating the effective flange width of the T-section,15 design codes were considered; ACI 318-14, ASC 2004, AS 3600-2017, BNBC 2015, BS 8110-1:1997, CSA A23,3-04, ECP 203-2018, Eurocode 8-2004, IRAQ 1-78, IS 456:2000, JSCE 2007, MS 2010, NZS 3101:2006, TS 500 and SBC 304-2007. The considered parameters were noticed to be varied from code to another. It was noticed that ACI 318-14, BNBC 2015, NZS 3101:2006 and SBC 304-2007 codes estimate the effective flange width regardless of distance between moment inflection points (beam continuity) inspite that others codes consider such effect. An illustrative example is presented in order to compare the results of different standards considering the continuity effect. It was found that for the same case of loading and concrete dimensions, significant variations were observed in all cases. Besides, dissimilar values were stipulated by design standards for the distance between inflection points. Therefore, this paper also aims to shed a light on the exact value of the factor multiplied by the span length to obtain the distance between inflection points. A linear finite element analysis is implemented to analyze the case study with 2 spans, 3 spans, 4 spans …. etc. On an average bases, these factors were 0.824 and 0.678 for external and internal span of continuous beam, respectively. Finally, analytical and experimental studies are required in order to reach the optimum flange width considered in the design process of RC T-section.