A technique can define a right position for forming a toner image on the transfer surface of an intermediate transfer body regardless of the size and the number of the sheets on which toner images are to be transferred. An image forming apparatus for forming a toner image on the transfer surface of an intermediate transfer body by correcting the position for forming the toner image comprises a data acquisition section that acquires predetermined data relating to the printing data for forming an image on a sheet and a correction section that corrects the predefined value for defining the position for forming the toner image on the transfer surface according to a predetermined correction value corresponding to the predetermined data acquired in the data acquisition section. Upon determining that toner images are formed simultaneously on the transfer surface for a plurality of pages according to the predetermined data, the correction section corrects the respective positions for forming the toner images, using the correction values respectively corresponding to the plurality of pages.