In this study, an engineering method is presented for computing normal force, pitching moment and center of pressure for missiles with square and rectangular cross sections. To predict normal force coefficient values for rectangular body, a formulation in generated by means of Newtonian theory in this study. An empirical correction factor is developed to modify Cdn values for noncircular cross sections. This semi-empirical method is applied to predict viscous separation crossflow and potential crossflow terms for body alone. Geometric variable considered in this study is the corner radius of cross section. CN and XCP values for bodies alone are computed for different Mach numbers. Predicted CN and XCp values obtained for the body agree well with the experimental results.