An image forming apparatus includes an image forming unit that has multiple developing units, arranged in series for basic colors in a rotational driving direction of a transfer body, for developing toner images of the basic colors based on input image data and forms the overlapped toner images on a surface of the transfer body in a state in which the toner images are aligned; a transferring unit that transfers the toner images onto a sheet; and a controller that calculates a difference between color information of an image obtained by reading the toner images and color information of the input image data, calculates a color change direction of the toner images with respect to a color of the input image data based on the difference, and refers to a table and determines a shape of a surface of the sheet based on information of the color change direction.