The implementation of the Wireless Power Consortium’s (WPC’s) Qi standard brings wireless power to many different end applications. The receiver (Rx) coil for each application may have different geometries and/or power requirements. Since the Rx coil is a key component in a successful design of a Qi-compliant Rx and there are many design options to consider, the designer must take a careful and methodical approach when realizing a solution. This paper provides the technical insight needed to realize a successful Rx-coil design. It covers the Qi-compliant system model as a basic transformer, Rx-coil measurements and system-level influences, and methods of qualifying a design for successful operation.