Crack width and crack spacing in concrete flexural members are affected by two parameters, namely, the bond stress between the steel and concrete, and the effective concrete area in tension. This paper presents a statistical study applying dimensional analysis and regression analysis to existing test data to evaluate these two parameters as well as the crack spacing and crack width. It is found that the crack spacing is strongly dependent on the diameter of reinforcing bars and the reinforcement ratio. It is also found that a reduction of steel stress should be considered in calculating the crack width. Based on the results of this study, equations are developed for the calculation of crack width in reinforced and prestressed flexural members.