Atlanta is about 1.3 times smaller than Wellington.

Wellington (map shows its 57 named neighbourhoods; the area covers the whole city) is approximately 444 sq km, while Atlanta (map shows its 114 named neighbourhoods; the area covers the whole city) is approximately 350 sq km, making Atlanta 78.94% the size of Wellington.
Tip: This to-scale comparison of Wellington vs. Atlanta uses the Mercator projection, which distorts the size of regions near the poles.
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