District of Columbia is about 4.6 times smaller than Kiribati.

Kiribati is approximately 811 sq km, while District of Columbia is approximately 177 sq km, making District of Columbia 21.82% the size of Kiribati. Meanwhile, the population of Kiribati is ~114,189 people (487,534 more people live in District of Columbia).
Tip: This to-scale comparison of Kiribati vs. District of Columbia uses the Mercator projection, which distorts the size of regions near the poles.