Boise, Idaho is 81% larger than Provo, Utah.
Area: 207 km2 calculated
Boise is the capital and most populous city of the U.S. state of Idaho, as well as the county seat of Ada County. Located on the Boise River in southwestern Idaho, the population of Boise at the 2010 Census was 205,671, the 99th largest in the nation. Its estimated population in 2013 was 214,237. Wikipedia
Area: 114 km2 calculated
Provo is the third-largest city in the U.S. state of Utah, located about 43 miles south of Salt Lake City along the Wasatch Front. Provo is the largest city and county seat of Utah County. It lies between the cities of Orem to the north and Springville to the south. Wikipedia