An image forming apparatus includes an image forming device that forms images in an image region on a sheet. An image fixing device includes heater elements disposed along a sheet-width direction. A controller is configured to identify a heater element that will overlap with an edge of the image region when a sheet is conveyed to the image fixing device. The controller calculates whether a shift of the image region by a shift amount less than a threshold would cause the heater element to not overlap. If so, the image forming device is controlled to form the image in a shifted image region and only those heater elements in the plurality of heater elements that overlap with the shifted image region are turned on when fixing the sheet if the image has been formed in the shifted image region.