New Zealand is about 1.2 times smaller than New Mexico.

New Mexico is approximately 314,310 sq km, while New Zealand is approximately 268,838 sq km, making New Zealand 85.53% the size of New Mexico. Meanwhile, the population of New Mexico is ~2.1 million people (3.0 million more people live in New Zealand).
Tip: This to-scale comparison of New Mexico vs. New Zealand uses the Mercator projection, which distorts the size of regions near the poles.