A driving controller includes: a grayscale determiner, which determines a current grayscale of input image data, a deterioration time determiner, which determines a first deterioration time for the current grayscale corresponding to an accumulated deterioration degree, a current deterioration degree calculator, which calculates a second deterioration time by summing the first deterioration time and a calculation period, and calculates a current deterioration degree for the current grayscale according to the second deterioration time, and an image compensator, which compensates the input image data based on the current deterioration degree.