This article presents the combination of two established models: (i) a physically motivated zero-dimensional model that describes the static behavior of planar anode supported SOFCs with high precision in the whole range of technically relevant operating conditions and (ii) a performance model for large area SOFC which expands the behavior of a small cell to a large cell by a discretization of the gas channel. Their combination yields the possibility to make predictions of performance and efficiency of an SOFC or SOEC stack operated in technically relevant operating conditions. Examples will demonstrate the capability of this model as well as the obtained results show that very good electrochemical efficiencies are possible with the state-of-the-art SOCs. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.