New York City is about 2.1 times smaller than Johannesburg.

Johannesburg is approximately 1,644 sq km, while New York City (including all five boroughs: Manhattan, Brooklyn, Queens, The Bronx, and Staten Island) is approximately 781 sq km, making New York City 47.51% the size of Johannesburg.
Tip: This to-scale comparison of Johannesburg vs. New York City uses the Mercator projection, which distorts the size of regions near the poles.
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