Sydney is about 20 times smaller than South Carolina.

South Carolina is approximately 77,983 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 4.89% the size of South Carolina.
Tip: This to-scale comparison of South Carolina vs. Sydney uses the Mercator projection, which distorts the size of regions near the poles.
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