A display apparatus includes: an external input port which is connectable with an external apparatus; a power supply; a display; and at least one processor configured to: obtain first power consumed in the display based on brightness information of the display, determine second power suppliable to the external input port based on the first power consumed and supply power of the power supply, receive information about third power that is configured to supply power to an external apparatus connected to the external input port from the external apparatus, determine fourth power supplied to the external input port based on the second power and the information about the third power, determine an over current protection (OCP) value based on the fourth power, and stop power supply to the external apparatus based on a current value supplied to the external input port exceeding the OCP value.