New Mexico is about 55 times bigger than Brunei.

Brunei is approximately 5,765 sq km, while New Mexico is approximately 314,310 sq km, making New Mexico 5,352% larger than Brunei. Meanwhile, the population of Brunei is ~478,054 people (1.6 million more people live in New Mexico).
Tip: This to-scale comparison of Brunei vs. New Mexico uses the Mercator projection, which distorts the size of regions near the poles.