A computer program for optimization of reinforced concrete cross section of an arbitrary shape loaded with combined biaxial bending and axial load is presented in the graduation thesis. The computation takes place in the Excel computer program, optimization is performed with the Solver Add–in. The perimeter of the cross section area is presented as a polygon, the steel reinforcment bars are input as points in the area. The stress-strain relationship of the conventional strength concrete and steel rebar are compliant with the EC2 code. Bernoulli’s assumption that plane sections remain plane is valid. By employing Green’s Theorem, the double integral of the longitudinal stresses is transformed to line integral along the cross sections perimeter. For each section of the polygon, the forces are computed. All equations on the section level are analytical in nature. The verification of the program is performed by comparing the results obtained on standard cross sections with results available in the literature. The application of the computer program is illustrated with asymetrical RC cross-section design example.