A display control method for an image forming apparatus includes detecting that a document is placed on a document reading unit, determining, when it is detected that the document is placed on the document reading unit, whether the size of the document is a predetermined size, displaying a first function screen on a display when a first function capable of performing one of a plurality of functions accompanying a reading operation for a document placed on the document reading unit is performed, and displaying a second function screen to which a screen is switched from the first function screen and that is displayed when a second function created by modifying the first function based on a specific setting is performed, in a case where, while the first function screen is displayed, it is determined that the size of the detected document is not the predetermined size.