Denton, Texas is 2.8 times larger than Round Rock, Texas.
Area: 247 km2 calculated
Denton is a city in the U.S. state of Texas and the county seat of Denton County. As of the 2010 United States Census, its population was 113,383, making it the 27th most populous city in Texas and the 11th-largest city in the Dallas–Fort Worth metroplex. Wikipedia
Area: 88 km2 calculated
Round Rock is a city in the state of Texas within the Greater Austin, Texas metropolitan area and Williamson County. The 2013 census estimate places the population at 109,821. Wikipedia