Sydney is about 4.9 times smaller than Anaheim.

Anaheim is approximately 130 sq km, while Sydney is approximately 27 sq km, making Sydney 20.5% the size of Anaheim.
Tip: This to-scale comparison of Anaheim 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.