Sydney is about 3.9 times smaller than Buffalo.

Buffalo is approximately 105 sq km, while Sydney is approximately 27 sq km, making Sydney 25.53% the size of Buffalo.
Tip: This to-scale comparison of Buffalo 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.