Accurate modeling of stress-retarded orientation-dependent 2-D oxidation is carried out by matching the experimental and simulated oxide thicknesses of silicon FIN nanostructures over a wide range of temperatures and times in dry oxygen. Experimentally observed initial oxidation rate enhancement, orientation-dependent stress retardation, and self-limiting phenomena are modeled, and a new universal stress retardation parameter set is obtained for the first time. The new parameter set has been validated against oxidation experiments presented here and those reported in the literature. Furthermore, the new model is used to explore silicon nanowire shape engineering.