California is about 1.9 times bigger than Belarus.

Belarus is approximately 207,600 sq km, while California is approximately 403,882 sq km, making California 95% larger than Belarus. Meanwhile, the population of Belarus is ~9.4 million people (27.8 million more people live in California).
Tip: This to-scale comparison of Belarus vs. California uses the Mercator projection, which distorts the size of regions near the poles.