An organic light emitting display device includes a display panel including a plurality of pixels, a scan driver configured to provide a scan signal to the pixels, a data driver configured to provide a data signal to the pixels, a sensing circuit configured to sense a sensing current flowing through the pixels according to a sensing reference voltage applied to the pixels, and a controller configured to calculate a sensing current variation from the sensing current, and configured to adjust the sensing current variation based on a variation data of the pixels to compensate an input image data.