Australia is about 43,736 times bigger than District of Columbia.

District of Columbia is approximately 177 sq km, while Australia is approximately 7,741,220 sq km, making Australia 4,373,471% larger than District of Columbia. Meanwhile, the population of District of Columbia is ~601,723 people (25.5 million more people live in Australia).
Tip: This to-scale comparison of District of Columbia vs. Australia uses the Mercator projection, which distorts the size of regions near the poles.