Maine is about 3.4 times bigger than New Hampshire.

New Hampshire is approximately 23,227 sq km, while Maine is approximately 79,931 sq km, making Maine 244% larger than New Hampshire. Meanwhile, the population of New Hampshire is ~1.3 million people (11,891 more people live in Maine).
Tip: This to-scale comparison of New Hampshire vs. Maine uses the Mercator projection, which distorts the size of regions near the poles.