Nauru is about 8 times smaller than District of Columbia.

District of Columbia is approximately 177 sq km, while Nauru is approximately 21 sq km, making Nauru 11.86% the size of District of Columbia. Meanwhile, the population of District of Columbia is ~601,723 people (591,912 fewer people live in Nauru).
Tip: This to-scale comparison of District of Columbia vs. Nauru uses the Mercator projection, which distorts the size of regions near the poles.