An image forming apparatus is configured that a developing unit develops a latent image with a toner, which is controlled by a toner-supply control unit based on a deference between a toner-density of the toner that is supplied to the developing unit and a reference-value. A reference-value determining unit determines the reference-value. A condition determining unit determines whether a predetermined condition is satisfied. The reference-value determining unit updates the reference-value with a different reference-value when the condition determining unit determines that the predetermined condition is satisfied.