Sydney is about 14 times smaller than Mesa.

Mesa (map shows its 6 named neighbourhoods; the area covers the whole city) is approximately 367 sq km, while Sydney is approximately 27 sq km, making Sydney 7.27% the size of Mesa.
Tip: This to-scale comparison of Mesa 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.