In a method and x-ray device to adapt the width and the position of a central value of a greyscale windowing for imaging with the x-ray device based on CT values determined with said x-ray device, the adaptation takes place within the scope of a determination and adjustment of an acquisition tube voltage of an x-ray tube of the x-ray device for an examination of a defined tissue of a patient, assuming a reference tube voltage for the examination of the defined tissue of the patient, and in which a width and position of a central value of the greyscale windowing that are associated with the reference tube voltage are automatically adapted to the acquisition tube voltage.