California is about 1,547 times bigger than Saint Kitts and Nevis.

Saint Kitts and Nevis is approximately 261 sq km, while California is approximately 403,882 sq km, making California 154,644% larger than Saint Kitts and Nevis. Meanwhile, the population of Saint Kitts and Nevis is ~54,488 people (37.2 million more people live in California).
Tip: This to-scale comparison of Saint Kitts and Nevis vs. California uses the Mercator projection, which distorts the size of regions near the poles.