An image forming apparatus including: an obtaining portion that divides image data into a plurality of regions in a sub scanning direction, and obtains, for each of the plurality of regions in the sub scanning direction, a first value relating to pixels having density at at least a prescribed value in a first width and a second value relating to pixels having density at at least the prescribed value in a second width, which is greater than the first width; a determining portion that determines, for each of the plurality of regions, a target temperature for maintaining a temperature of a heating member on the basis of the first and second values; and a control portion that controls power supplied to the heating member so that the temperature of the heating member is maintained at the target temperature.