A display apparatus including a display panel, a display driver, a controller and an external circuit is introduced. The display drive includes a power circuit that supplies a first voltage and a second voltage to the display panel to sense a plurality of sensing currents flowing through the display panel according to the first voltage and the second voltage in a first operating mode. The display driver receives the plurality of sensing currents and a target current from the display panel in the first operating mode. The controller is coupled to the display driver and configured to determine a plurality of offsets according to the plurality of sensing currents and the target current in the first operating mode. The external memory is coupled to the controller and the display driver to store the offsets in the first operating mode. The display driver and a method adapted to a display apparatus are also introduced.