A display device includes a display panel including a plurality of pixels, a timing controller, a data driver and a scale factor. The timing controller calculates a frame load value corresponding to an image frame of input image data and generates image data by scaling grayscale values of the input image data using a scale factor. The data driver generates a data signal corresponding to the image data and supplies the data signal to the pixels. The scale factor generating circuit sets a reference range based on a temperature of the display panel and a global current value that flows through the pixels, and generates the scale factor included within the reference range based on the frame load value and the global current value.