An organic light-emitting display device includes: a display panel; a deterioration threshold value calculator for calculating a deterioration threshold value from values of accumulated image data respectively input to the plurality of pixels; a current sensor for detecting a current amount flowing through pixels in one of first to nth display areas of the display panel in a power-off section of the display panel; and a deterioration amount calculator for defining a deterioration area including a group of pixels from among the pixels each having a value of image data that is equal to or greater than the deterioration threshold value among pixels in the first to nth display areas, and calculating a deterioration amount of the pixels in the deterioration area, wherein the current sensor is configured to detect a current amount flowing through pixels in one of the first to nth display areas in each power-off section.