District of Columbia is about 603 times smaller than Tennessee.

Tennessee is approximately 106,752 sq km, while District of Columbia is approximately 177 sq km, making District of Columbia 0.17% the size of Tennessee. Meanwhile, the population of Tennessee is ~6.3 million people (5.7 million fewer people live in District of Columbia).
Tip: This to-scale comparison of Tennessee vs. District of Columbia uses the Mercator projection, which distorts the size of regions near the poles.