An image forming apparatus generates a color image on a transfer belt by superimposing toner images of respective colors generated by image forming units, and transfers the color image onto a transfer medium. The image forming apparatus includes a correction pattern forming unit configured to form a correction pattern for correcting color misalignment on the transfer belt, a detection sensor configured to detect the correction pattern formed on the transfer belt by the correction pattern forming unit, and a correction control unit configured to control a width of the correction pattern in response to an output of the detection sensor produced by detecting the correction pattern.