Abstract: A computer-implemented method for calculating a nominal profile for the movement of an injection actuator of a molding machine includes defining a simulation domain comprising at least one cavity of a mold installed on the molding machine. At least one simulation is performed in the simulation domain, and injection of a molding material into the at least one cavity of the mold is simulated by predefining at least one volume flow profile through an inlet face at the edge of the simulation domain and/or by predefining at least one pressure profile at the inlet face as boundary condition. A volume flow profile calculated using the simulation and/or the at least one volume flow profile is converted into a nominal profile for the movement of an injection actuator, in particular a plasticizing screw, and a compressibility of the molding material is taken into account in the conversion.