A plug-in hybrid electric vehicle (PHEV), which has an engine and a motor and travels using a power of the engine and an electric power of the motor, includes: a battery configured to supply a drive energy of the motor; a battery sensor configured to measure a state of charge (SOC) of the battery; and a controller configured to estimate an average mileage per cycle established using traveling information of the vehicle, estimate an average SOC per cycle using the measured SOC, and control a reference power needed for driving the engine according to the estimated average mileage and the estimated average SOC.