Several building codes such as ANSI/AISC 360-16 and EC3 EN 1993-1-1 require the use of a proper design method to consider instability and second-order load effect problems for individual system elements and the entire structural system. Various methods are available to assess stability. All of these methods should consider P-Delta and P-delta effects (second-order effects). The following calculation procedures are presented in this study: (a) a simplified method is developed for P-Delta and P-delta analysis in regular frames under the effect of constant axial loads to obtain story drifts and end moments; (b) this method can be applied to an entire building or any individual story, that is, story-based design is possible; and (c) column effective length factors are obtained for individual columns. In addition, design tables are presented.