Oklahoma is about 383 times bigger than Northern Mariana Islands.

Northern Mariana Islands is approximately 464 sq km, while Oklahoma is approximately 177,847 sq km, making Oklahoma 38,229% larger than Northern Mariana Islands. Meanwhile, the population of Northern Mariana Islands is ~51,475 people (3.7 million more people live in Oklahoma).
Tip: This to-scale comparison of Northern Mariana Islands vs. Oklahoma uses the Mercator projection, which distorts the size of regions near the poles.