District of Columbia is about 582 times smaller than Iceland.

Iceland is approximately 103,000 sq km, while District of Columbia is approximately 177 sq km, making District of Columbia 0.17% the size of Iceland. Meanwhile, the population of Iceland is ~357,603 people (244,120 more people live in District of Columbia).
Tip: This to-scale comparison of Iceland vs. District of Columbia uses the Mercator projection, which distorts the size of regions near the poles.