Wellington is about 3.3 times smaller than Mexico City.

Mexico City is approximately 1,485 sq km, while Wellington (map shows its 57 named neighbourhoods; the area covers the whole city) is approximately 444 sq km, making Wellington 29.9% the size of Mexico City.
Tip: This to-scale comparison of Mexico City vs. Wellington 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.