Saint Helena, Ascension, and Tristan da Cunha is about 2.2 times bigger than District of Columbia.

District of Columbia is approximately 177 sq km, while Saint Helena, Ascension, and Tristan da Cunha is approximately 394 sq km, making Saint Helena, Ascension, and Tristan da Cunha 123% larger than District of Columbia. Meanwhile, the population of District of Columbia is ~601,723 people (593,798 fewer people live in Saint Helena, Ascension, and Tristan da Cunha).
Tip: This to-scale comparison of District of Columbia vs. Saint Helena, Ascension, and Tristan da Cunha uses the Mercator projection, which distorts the size of regions near the poles.