North Dakota is about 66 times bigger than Rhode Island.

Rhode Island is approximately 2,706 sq km, while North Dakota is approximately 178,647 sq km, making North Dakota 6,502% larger than Rhode Island. Meanwhile, the population of Rhode Island is ~1.1 million people (379,976 fewer people live in North Dakota).
Tip: This to-scale comparison of Rhode Island vs. North Dakota uses the Mercator projection, which distorts the size of regions near the poles.