Cambodia is about 1,023 times bigger than District of Columbia.

District of Columbia is approximately 177 sq km, while Cambodia is approximately 181,035 sq km, making Cambodia 102,180% larger than District of Columbia. Meanwhile, the population of District of Columbia is ~601,723 people (16.1 million more people live in Cambodia).
Tip: This to-scale comparison of District of Columbia vs. Cambodia uses the Mercator projection, which distorts the size of regions near the poles.