A heating device includes an belt, a heater contacting the belt and divided into heater blocks, a pressing member pressing a sheet against the belt, a temperature sensor disposed on a number of the heater blocks being at least one-half of a total number of the blocks, and a processor configured to select heater blocks based on a width of the sheet, select first temperature sensors on the selected heater blocks not having a non-paper passing region and control electric power supplied to the heater blocks so that temperatures detected by the first sensors are within a predetermined range, and select second temperature sensors on the selected heater blocks having the non-paper passing region and control electric power supplied to the heater blocks having the non-paper passing region to protect against an excessive temperature rise in the non-paper passing region based on second temperatures detected by the second sensors.