One of the most widespread practical methods of polymer processing is the extrusion method that is based on pressing a polymeric melt through channels of the molding tool which have different geometrical cross sections. The principal technical characteristic of extruders, named flow/pressure balance, and also modeling of deformation processes permit to evaluate their practical output in processing various polymers as a function of the hydraulic resistance which depends on the flow of an extruded polymeric material through the channels of the forming tool. The validity of obtained and presented results permits to recommend them reasonably not only for estimation of extruder output but also for making calculations necessary in extruder equipment design: checking calculation of strength and stability of a screw, calculation of driving power of the equipment being designed, strength calculation of a plasticizing cylinder, etc. POLYM. ENG. SCI., 50:2069-2073, 2010. (C) 2010 Society of Plastics Engineers