Gainesville, Florida is 2.1 times larger than Boulder, Colorado.
Area: 68 km2 calculated
Boulder is the county seat and most populous city of Boulder County and the 11th most populous city in the U.S. state of Colorado. Boulder is located at the base of the foothills of the Rocky Mountains at an elevation of 5,430 feet. The city is 25 miles northwest of Denver. Wikipedia
Area: 145 km2 calculated
Gainesville is the county seat and largest city in Alachua County, Florida, and the principal city of the Gainesville, Florida Metropolitan Statistical Area. The population of Gainesville in the 2010 United States Census was 124,354. Wikipedia