A display device includes a pixel unit including scan lines, data lines crossing the scan lines, and pixels connected to the scan lines and the data lines; a timing control unit configured to receive first data from an outside; a conversion unit configured to receive the first data from the timing control unit, to extract luminance components of the first data corresponding to the pixels to determine luminance distribution of the first data, to divide the luminance distribution into a plurality of luminance distribution ranges, and to convert the first data into second data by regulating an input gray level of the first data based on a conversion equation corresponding to a variation between data of the luminance distribution ranges; and a data drive unit configured to receive the second data from the conversion unit and to provide the second data to the data lines.