District of Columbia is about 525 times smaller than Indiana.

Indiana is approximately 92,895 sq km, while District of Columbia is approximately 177 sq km, making District of Columbia 0.19% the size of Indiana. Meanwhile, the population of Indiana is ~6.5 million people (5.9 million fewer people live in District of Columbia).
Tip: This to-scale comparison of Indiana vs. District of Columbia uses the Mercator projection, which distorts the size of regions near the poles.