An image forming apparatus includes an image forming unit including rotary members to form a toner image corresponding to image data, in which the image forming unit forms a toner pattern for detecting image density fluctuation; and an image forming condition determination controller to perform image forming processing to ultimately transfer the toner image onto a recording medium. In the image forming apparatus, the controller measures a periodic image density fluctuation occurring in a rotation cycle of the rotary members based on a detection result of a toner pattern; performs image forming condition determination processing to determine an image forming condition to reduce the image density fluctuation based on measured image density fluctuation data; and determines whether or not the image density fluctuation data measured multiple times satisfies a predetermined control termination condition.