Saint Lucia is about 173 times smaller than Tennessee.

Tennessee is approximately 106,752 sq km, while Saint Lucia is approximately 616 sq km, making Saint Lucia 0.58% the size of Tennessee. Meanwhile, the population of Tennessee is ~6.3 million people (6.2 million fewer people live in Saint Lucia).
Tip: This to-scale comparison of Tennessee vs. Saint Lucia uses the Mercator projection, which distorts the size of regions near the poles.