When a preview image is displayed, an area on which a certain finishing process is executed is automatically enlarged and displayed. A control method for controlling an image forming apparatus including a display unit for previewing print results obtained by printing print information to be printed, the control method comprising: determining a preview position and a preview magnification rate of the print results to be displayed on the display unit, based on a post-processing setting for the print information; and controlling a preview of the print results to be displayed on the display unit, based on the determined preview position and preview magnification rate.