Maine is about 4.7 times smaller than Japan.

Japan is approximately 377,915 sq km, while Maine is approximately 79,931 sq km, making Maine 21.15% the size of Japan. Meanwhile, the population of Japan is ~124.2 million people (122.9 million fewer people live in Maine).
Tip: This to-scale comparison of Japan vs. Maine uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.