Conceptual design studies have been carried out at the Fusion Engineering Design Center (FEDC) on a succession of tokamak devices. In order to quickly assess the technical feasibility and to estimate the costs of competing poloidal field (PF) systems, it is desirable to develop simple, but accurate, rules for the structural design of these coils. In this paper we describe the rules developed for superconducting ring coils and illustrate their application to a specific example. This methodology may be easily adapted to resistive ring coil design.