North Dakota is about 8 times bigger than New Hampshire.

New Hampshire is approximately 23,227 sq km, while North Dakota is approximately 178,647 sq km, making North Dakota 669% larger than New Hampshire. Meanwhile, the population of New Hampshire is ~1.3 million people (643,879 fewer people live in North Dakota).
Tip: This to-scale comparison of New Hampshire vs. North Dakota uses the Mercator projection, which distorts the size of regions near the poles.