Luxembourg is 15 times larger than Washington, D.C..
Area: 2,586 km2 World Factbook
Population: 520,672 (July 2014) World Factbook
Luxembourg, officially the Grand Duchy of Luxembourg, is a landlocked country in Western Europe. It is bordered by Belgium to the west and north, Germany to the east, and France to the south. 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