Several design equations exist for the design of the volumetric ratio of transverse reinforcement. However, there is no consistency between the requirements for confinement within these equations, nor do they allow the designer to account for a desired ductility. For this reason, a parametric study was performed to develop an equation that determines the minimum quantity of Grade 60 spiral reinforcement necessary to achieve a target ductility over a given range of axial loads in prestressed concrete piles. LPILE analyses were performed to establish permissible displacement limits of a pile confined by the volumetric ratio of transverse reinforcement called for by the developed equation.