Charlotte, North Carolina is 4.3 times larger than Sioux Falls, South Dakota.
Area: 733 km2 calculated
Charlotte is the largest city in the U.S. state of North Carolina and the seat of Mecklenburg County. In 2013, the estimated population of Charlotte according to the U.S. Census Bureau was 792,862, making it the 16th largest city in the United States based on population. Wikipedia
Area: 170 km2 calculated
Sioux Falls is the largest city in the U.S. state of South Dakota. It is the county seat of Minnehaha County, and also extends into Lincoln County to the south. Wikipedia