Saint Lucia is about 344 times smaller than Kansas.

Kansas is approximately 211,900 sq km, while Saint Lucia is approximately 616 sq km, making Saint Lucia 0.29% the size of Kansas. Meanwhile, the population of Kansas is ~2.9 million people (2.7 million fewer people live in Saint Lucia).
Tip: This to-scale comparison of Kansas vs. Saint Lucia uses the Mercator projection, which distorts the size of regions near the poles.