Croatia is around the same size as West Virginia.

West Virginia is approximately 62,361 sq km, while Croatia is approximately 56,594 sq km, making Croatia 90.75% the size of West Virginia. Meanwhile, the population of West Virginia is ~1.9 million people (2.3 million more people live in Croatia).
Tip: This to-scale comparison of West Virginia vs. Croatia uses the Mercator projection, which distorts the size of regions near the poles.