Ōita is the most populous city in Ōita Prefecture. As of June 30, 2011, the city has an estimated population of 475,861, with 205,639 households and a population density of 949.35 persons per km². The total area of the city is 501.25 km². The city is bordered by City of Beppu to the northwest, City of Yufu to the west, City of Taketa to the southwest, City of Bungo-ōno to the south, and City of Usuki to the southeast. The north of the city faces Beppu Bay and the Seto Inland Sea.