California is a state in the Western United States that lies on the Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares an international border with the Mexican state of Baja California to the south. With almost 40 million residents across an area of 163,696 square miles (423,970 km²), it is the largest state by population, third-largest state by area and the largest state economy in the U.S., with a GDP of approximately $4.3 trillion.