An image forming apparatus includes a roll that is a print medium in a roll-like shape; a conveyor for conveying the print medium that is pulled out from the roll; a conveyance controller for controlling a driving source of the conveyor, so that a conveyance amount of the print medium reaches a target conveyance amount; a detector for detecting information that is correlated with power increase of the driving source during conveyance of the print medium; and a corrector correcting, when the information that is correlated with the power increase of the driving source is detected, the target conveyance amount toward an increasing direction.