Auckland is about 14 times bigger than Detroit.

Detroit (map shows its 92 named neighbourhoods; the area covers the whole city) is approximately 359 sq km, while Auckland is approximately 4,894 sq km, making Auckland 1,262% larger than Detroit.
Tip: This to-scale comparison of Detroit vs. Auckland 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.