District of Columbia is about 626 times smaller than Bulgaria.

Bulgaria is approximately 110,879 sq km, while District of Columbia is approximately 177 sq km, making District of Columbia 0.16% the size of Bulgaria. Meanwhile, the population of Bulgaria is ~6.9 million people (6.3 million fewer people live in District of Columbia).
Tip: This to-scale comparison of Bulgaria vs. District of Columbia uses the Mercator projection, which distorts the size of regions near the poles.
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