Various numerical models of diagonally stiffened steel plate shear wall were tested under push-over loads to study the required stiffness of columns of diagonally stiffened SPSWs. This research presents a parametric study to explore the influence of varying the infill panel’s thickness, width, and height and the number of floors on the stiffness of the edge columns, and to propose expressions to predict the column’s in-plane stiffness and area required for preliminary design. Different SPSWs were modeled with a range of several stories, an aspect ratio, and height to thickness ratio, respectively, of (n=3-7), (Lp /hp=1-2), and (λ=200-400). The results indicated that the number of floors (n) has a great effect on the wall’s shear capacity. A greater number of floors lead to buckling in columns and early failure of the system, and subsequently, an increase in the column’s rigidity is required. Moreover, an equation is proposed to calculate the value of ωh required for sufficient inertia of the column. Higher the drift is, lower the shear capacity of the wall is, particularly for walls with a larger aspect ratio (Lp /hp > 1.5), and smaller height to thickness ratio (λ < 400). It is proposed that the columns’ out-of-plane stiffness divided by its in-plane stiffness to be equal or greater than 0.4. An equation is also proposed to predict the required columns’ rx substantial to assure that the columns can resist the impact of the tension field and the plate achieves full yield strength.