A display device includes a display panel, a first memory, and a degradation compensator. The first memory device stores stress data including degradation values representing a degradation degree of each of the blocks in the display panel. The degradation compensator loads the stress data from the first memory device, updates the stress data based on current input data and a maximum degradation value, updates the maximum degradation value based on degradation values included in the updated stress data, and generate compensated data by compensating for the current input data based on the updated stress data. The degradation compensator determines whether a first degradation value included in the stress data is normal by comparing the first degradation value with the maximum degradation value, and updates the first degradation value based on at least one adjacent degradation value adjacent to the first degradation value, when the first degradation value is abnormal.