Screw conveyors are established and proven conveyors for bulk material, where the conveying element is a screw. This rotates about its axis and transports the bulk material in axial direction in a stationary trough that also serves as carrying element. In this standard the proper and standardized dimensioning of vertical operated screw conveyors is described. Thereby an appropriate size fitting to the application as well as the necessary power for the conveying task can be determined.