Quantum confinement effects (QCEs) are significant in tunnel field-effect transistors (TFETs) since their operation is based on the mechanism of band-to-band tunneling. This study presents a simple approach for integrating QCEs into the semiclassical TCAD simulations of TFETs. The approach was based on a post-processing computation in which 1D Schrodinger equations were first solved manually, then their solutions were used to modify the conduction and valence band profiles in the 2D TCAD simulations. For each bias condition, only a 1D potential profile at the position of the maximum tunneling generation was adopted to describe the QC through the solutions of Schrodinger equations for electrons and holes. The quantum-simulated results based on this simple method show good agreements with both quantum–mechanical simulations based on a sophisticated approach and experimental data. The analyses also show that the van Dort quantum model available in commercial TCAD simulators is not appropriate for describing QCEs in TFETs. The approach can be practically employed in studying the influences of QCEs on the electrical characteristics, in particular the dependence of QCEs on the body thickness of TFET devices.