New Mexico is about 4.1 times smaller than Chad.

Chad is approximately 1,284,000 sq km, while New Mexico is approximately 314,310 sq km, making New Mexico 24.48% the size of Chad. Meanwhile, the population of Chad is ~18.0 million people (15.9 million fewer people live in New Mexico).
Tip: This to-scale comparison of Chad vs. New Mexico uses the Mercator projection, which distorts the size of regions near the poles.