Greece is about 746 times bigger than District of Columbia.

District of Columbia is approximately 177 sq km, while Greece is approximately 131,957 sq km, making Greece 74,452% larger than District of Columbia. Meanwhile, the population of District of Columbia is ~601,723 people (9.9 million more people live in Greece).
Tip: This to-scale comparison of District of Columbia vs. Greece uses the Mercator projection, which distorts the size of regions near the poles.