A method for operating a valve device for supplying compressed air to compressed air consumer includes the steps of: determination of a first fluid pressure in a first section of a fluid passage of a valve assembly, which extends between an inlet port, and a valve element, determination of a second fluid pressure in a second section of the fluid passage of the valve assembly, which extends between the valve element and an outlet port, determination of a flow value for the valve element from the two fluid pressures and of a flow function, relating of the flow value with a presettable volumetric fluid flow rate or mass fluid flow rate for the pressurised fluid, which flow rate is provided for flow through the fluid passage, to a guide value and determination of a required actuating energy for an actuating device, and provision of the actuating energy to the actuating device.