Rhode Island is about 15 times bigger than Marshall Islands.

Marshall Islands is approximately 181 sq km, while Rhode Island is approximately 2,706 sq km, making Rhode Island 1,395% larger than Marshall Islands. Meanwhile, the population of Marshall Islands is ~79,906 people (972,661 more people live in Rhode Island).
Tip: This to-scale comparison of Marshall Islands vs. Rhode Island uses the Mercator projection, which distorts the size of regions near the poles.