Abstract: In the design of flexural members, the calculation of the cross-sectional flexural capacity is essential. Although the current design software can be applied to calculate beam, plate and column reinforcements, it is necessary for the beam of brick and concrete to be calculated by hand so as to attain more safety in general. Since so many formulae would be used and the calculation process is relatively complex, the basic formula has been developed to obtain a simple formulation by simplifying the calculation process in the paper. The cross-section flexural capacity calculation would be ready if the given variables were directly substituted into the simplified formula, which would make the structural design convenient for engineer designers.