A wireless power transmitter is provided. The wireless power transmitter includes an inverter configured to output alternating current (AC) power using direct current (DC) power, a coil configured to receive the AC power, and a control circuitry, wherein the control circuitry is configured to identify an input associated with transmitting the AC power, output the AC power at a specified frequency determined according to the input, using the inverter, transmit the AC power to an external electronic device using the coil, and, while at least partially transmitting the AC power to the external electronic device, transmit information associated with an amount of the DC power input to the inverter to output the AC power to the external electronic device, such that the external electronic device identifies transmission efficiency of the AC power using the information associated with the amount of DC power.