A display device includes: a pixel part to display an image and including pixels receiving a reference voltage; a controller to determine a value of the reference voltage based on a load of the entire pixel part, and to control a grayscale range of image data according to a location in the pixel part based on the reference voltage; a data driver to supply data voltages to the pixel part through data lines based on grayscale ranges adjusted for each location in the pixel part; and a scan driver to supply a scan signal to the pixels through scan lines.