The exact calculation of the extruder sizes in an extrusion line for tyre profile manufacturing requires precise knowledges not only of the planned capacities and dimensions but also of the consistences and processing proper ties of the compound. Since often only incomplete informations are available and since not always trials with the intended compound can be carried out, the lay out of the line in such cases has to be made according to experience and estimations. The present paper provides standard values for typical applications in tyre profile extrusion and shows graphs for the relationships between the different performance data. Herein the compound properties, the profile dimensions and the running parameters are taken into consideration. By this an estimation of the extruder sizes will be possible, even if no complete informations are available.