A display device includes: a display panel including pixels; a timing controller configured to generate image data based on input image data; a data driver configured to generate a data signal corresponding to the image data and supplying the data signal to the pixels; a power supply configured to supply a first power supply voltage to the display panel; and a power controller configured to calculate a load value and a peak grayscale of the entire display panel based on the input image data, receive feedback voltages of the first power supply voltage from relatively lower quality areas in which IR drop of the first power supply voltage occurs relatively more frequently, and generate a power control signal for changing the level of the first power supply voltage based on the load value, the peak grayscale, and the feedback voltages.