Slovakia is about 1.3 times smaller than West Virginia.

West Virginia is approximately 62,361 sq km, while Slovakia is approximately 49,035 sq km, making Slovakia 78.63% the size of West Virginia. Meanwhile, the population of West Virginia is ~1.9 million people (3.6 million more people live in Slovakia).
Tip: This to-scale comparison of West Virginia vs. Slovakia uses the Mercator projection, which distorts the size of regions near the poles.