Mexico City is about 3.3 times smaller than Auckland.

Auckland is approximately 4,894 sq km, while Mexico City is approximately 1,485 sq km, making Mexico City 30.34% the size of Auckland.
Tip: This to-scale comparison of Auckland vs. Mexico City uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.