Sydney is about 4.9 times bigger than New York City.

New York City (including all five boroughs: Manhattan, Brooklyn, Queens, The Bronx, and Staten Island) is approximately 781 sq km, while Sydney (the 30 councils of metropolitan Sydney, without the Blue Mountains, Hawkesbury, Wollondilly and the Central Coast) is approximately 3,810 sq km, making Sydney 388% larger than New York City.
Tip: This to-scale comparison of New York City vs. Sydney uses the Mercator projection, which distorts the size of regions near the poles.
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