Sydney is about 17 times smaller than Wellington.

Wellington (map shows its 57 named neighbourhoods; the area covers the whole city) is approximately 444 sq km, while Sydney is approximately 27 sq km, making Sydney 6.01% the size of Wellington.
Tip: This to-scale comparison of Wellington vs. Sydney 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.