Wyoming is about 1.2 times smaller than New Mexico.

New Mexico is approximately 314,310 sq km, while Wyoming is approximately 251,489 sq km, making Wyoming 80.01% the size of New Mexico. Meanwhile, the population of New Mexico is ~2.1 million people (1.5 million fewer people live in Wyoming).
Tip: This to-scale comparison of New Mexico vs. Wyoming uses the Mercator projection, which distorts the size of regions near the poles.