Seattle is about 18 times smaller than Melbourne.

Melbourne (the 27 councils of metropolitan Melbourne, without the Yarra Ranges, Cardinia, Mornington Peninsula and Nillumbik) is approximately 3,915 sq km, while Seattle is approximately 217 sq km, making Seattle 5.55% the size of Melbourne.
Tip: This to-scale comparison of Melbourne vs. Seattle uses the Mercator projection, which distorts the size of regions near the poles.
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