Disclosed herein are stability display apparatus and methods. One apparatus comprises a driving state detection unit configured to detect a driving state of a vehicle in operation; a controller comprising an instability estimation unit configured to estimate an instability index indicating driving instability of the vehicle based on the driving state of the vehicle detected by the driving state detection unit and configured to determine changes in the instability index; and a display unit configured to display the instability index estimated by the instability estimation unit in a display region within a range less than or equal to an upper limit that is a limit of display and configured to display in the display region a representation of the changes of the instability index when the instability index is beyond the upper limit.