Melbourne is about 7 times bigger than Chicago.

Chicago is approximately 590 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 564% larger than Chicago.
Tip: This to-scale comparison of Chicago vs. Melbourne uses the Mercator projection, which distorts the size of regions near the poles.
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