New Mexico is around the same size as Republic of the Congo.

Republic of the Congo is approximately 342,000 sq km, while New Mexico is approximately 314,310 sq km, making New Mexico 91.9% the size of Republic of the Congo. Meanwhile, the population of Republic of the Congo is ~5.5 million people (3.5 million fewer people live in New Mexico).
Tip: This to-scale comparison of Republic of the Congo vs. New Mexico uses the Mercator projection, which distorts the size of regions near the poles.