Fort Worth is the fifth-largest city in the U.S. state of Texas and the 13th-largest city in the United States. It is the county seat of Tarrant County, covering nearly 350 sqmi into three other counties: Denton, Parker, and Wise. According to the 2018 census estimates, Fort Worth's population was 898,919. Fort Worth is the city in the Dallas–Fort Worth–Arlington metropolitan area, which is the 4th most populous metropolitan area in the United States.