An image forming apparatus includes: a communication unit that receives first mode electric power to perform communication; an image forming unit that receives first mode electric power to form an image on a medium; a fixing unit that generates heat by receiving first mode electric power, and performs a fixing process of fixing the image to the medium; a predicting unit that predicts a processing time required for a process of forming the image; and a supply controller that controls supply of electric power according to a first mode or a second mode in which power consumption is smaller than that of the first mode. The supply controller starts the supply of first mode electric power to the fixing unit at a timing based on the predicted processing time when the image forming apparatus transitions from the second mode to the first mode.