San Francisco is about 2.4 times smaller than Fort Wayne.

Fort Wayne (map shows its 315 named neighbourhoods; the area covers the whole city) is approximately 289 sq km, while San Francisco (including the city proper only) is approximately 121 sq km, making San Francisco 41.8% the size of Fort Wayne.
Tip: This to-scale comparison of Fort Wayne vs. San Francisco uses the Mercator projection, which distorts the size of regions near the poles.
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