Sydney is about 2.5 times smaller than Arlington.

Arlington (map shows its 62 named neighbourhoods; the area covers the whole city) is approximately 67 sq km, while Sydney is approximately 27 sq km, making Sydney 39.65% the size of Arlington.
Tip: This to-scale comparison of Arlington 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.