Dynamic influences such as shear rates have an impact on the incorporation behaviour of fibers. In the development phase of new models, computer-aided three-dimensional CFD simulations are used to map the results to real processes. Fluid mechanics are offering an established method with numerical simulations to solve fluid mechanical problems. In this context, the paper provides an quantitative analysis of the shear rates for different threading elements based on the different flow areas (gusset, channel, gap) for twin screw extruders. Material and screw speeds are varied to the show the corrosponding effects on the shear rate. Within the investigation series, the numerical investigation results are compared with the analytical description of the shear rate. For the analytical description, the commonly known calculation method after SCHULER is used. Furthermore, the mass flow for the different flow areas are determined to define a relation to the total shear rate in the element. The aim of the work is to evaluate the results of the CFD simulations in dependence of flow conditions and to extend the analytical calculation if necessary. From these investigations, it is afterwards possible to conclude a better quality in other modelling approaches such as fiber breakage in the twin-screw process.