Melbourne is around the same size as Sydney.

Sydney (the 30 councils of metropolitan Sydney, without the Blue Mountains, Hawkesbury, Wollondilly and the Central Coast) is approximately 3,810 sq km, while Melbourne (the 27 councils of metropolitan Melbourne, without the Yarra Ranges, Cardinia, Mornington Peninsula and Nillumbik) is approximately 3,915 sq km, making Melbourne 3% larger than Sydney.
Tip: This to-scale comparison of Sydney vs. Melbourne uses the Mercator projection, which distorts the size of regions near the poles.
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