Washington, D.C. is 11% larger than Columbia, Missouri.
Area: 161 km2 calculated
Columbia is a city of 115,276 people in Missouri, a state of the American Midwest. Founded in 1818 as the county seat of Boone County and home to the University of Missouri, it is the principal municipality of the Columbia Metropolitan Area, the fourth most populous urban area in Missouri. Wikipedia
Area: 178 km2 calculated
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. Wikipedia