An inflatable panel is an airtight membrane structure whose envelope has two parallel flat sides when pressurized. It acquires load-carrying capacity due to its internal pressure. While pressurized tubes have been studied extensively over the past decades, panels were less investigated. In this work, a model of inflatable panels including shear effects is proposed. The nonlinear equations of motion are derived from the principle of virtual power within the framework of finite deformations and exhibit the essential pressure terms that allow for the correct prediction of the panel behavior. The equations are then linearized around the pre-stressed reference configuration and solved for a simply-supported circular panel subjected to a uniform load. The solution is found to be in good agreement with 3D finite element results.