Maine is around the same size as Panama.

Panama is approximately 75,420 sq km, while Maine is approximately 79,931 sq km, making Maine 6% larger than Panama. Meanwhile, the population of Panama is ~4.3 million people (3.0 million fewer people live in Maine).
Tip: This to-scale comparison of Panama vs. Maine uses the Mercator projection, which distorts the size of regions near the poles.