New Hampshire is about 16 times smaller than Montana.

Montana is approximately 376,979 sq km, while New Hampshire is approximately 23,227 sq km, making New Hampshire 6.16% the size of Montana. Meanwhile, the population of Montana is ~989,415 people (327,055 more people live in New Hampshire).
Tip: This to-scale comparison of Montana vs. New Hampshire uses the Mercator projection, which distorts the size of regions near the poles.