This paper presents a non-Isothermal numerical model developed at the KTP for calculating the drive power of single-screw plasticating units. It includes, firstly, a description of the mathematical and physical modeling process and, secondly, an explanation of the systematic approach, based on statistical methods, that was adopted for compiling an approximation equation with the aid of non-isothermal, three-dimensional FEA flow simulation results. In addition, the generated model is verified on the basis of the computation results obtained with a simulation program for screw layout, in which the model was implemented. The simulation results are compared with experimentally recorded power data for selected extrusion and injection molding processes and the quality of the model is subsequently assessed.