Sydney is about 1.6 times bigger than Cape Town.

Cape Town is approximately 2,455 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 55% larger than Cape Town.
Tip: This to-scale comparison of Cape Town vs. Sydney uses the Mercator projection, which distorts the size of regions near the poles.
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