Maine is around the same size as Czech Republic.

Czech Republic is approximately 78,867 sq km, while Maine is approximately 79,931 sq km, making Maine 1% larger than Czech Republic. Meanwhile, the population of Czech Republic is ~10.7 million people (9.4 million fewer people live in Maine).
Tip: This to-scale comparison of Czech Republic vs. Maine uses the Mercator projection, which distorts the size of regions near the poles.