This is an extrusion rate calculator for flighted feed screws used in thermoplastic melt processing. The calculation is based on standard extruder screw geometry. Initially the calculation assumes a specific gravity of 1.0 g/cc. You can improve the accuracy of the calculation by entering the specific gravity of your polymer. Large diameter screw run at high RPMs will calculate very high rates not normally achievable in practice. Limit the RPMs to give a maximum 30 in/sec tip velocity. No compensation is given for high discharge pressures.