New Mexico is about 3.1 times bigger than South Korea.

South Korea is approximately 99,720 sq km, while New Mexico is approximately 314,310 sq km, making New Mexico 215% larger than South Korea. Meanwhile, the population of South Korea is ~51.8 million people (49.8 million fewer people live in New Mexico).
Tip: This to-scale comparison of South Korea vs. New Mexico uses the Mercator projection, which distorts the size of regions near the poles.