An image forming apparatus includes: a forming unit configured to form an image on an image carrier; a holding unit configured to hold a reference table and a tone correction table that convert a plurality of input image data values into corresponding output image data values; and a correcting unit configured to control the forming unit to form a first test pattern including a plurality of images having different densities on the image carrier using the tone correction table, and correct the tone correction table by detecting densities of the plurality of images. The correcting unit is further configured to correct the tone correction table by updating the tone correction table using the detected densities of the plurality of images and then interpolating the updated tone correction table using the reference table.