According to an aspect, a display device includes: a display unit; a lighting unit emitting internal light; a measurement unit; and a control unit controlling an intensity of the internal light and a gradation value of each pixel in the display unit. The control unit calculates a required luminance value for a luminance value of a pixel to be N times as high as a luminance value indicated by an input signal, the pixel performing output with the largest gradation value out of the pixels in a predetermined image display region. The control unit determines the intensity of the internal light based on an intensity of the external light measured by the measurement unit and the required luminance value, and calculates an output gradation value based on the gradation value indicated by input signal, the intensity of the external light, and the intensity of the internal light.