San Francisco is around the same size as Kaiserslautern.

Kaiserslautern is approximately 140 sq km, while San Francisco (including the city proper only) is approximately 121 sq km, making San Francisco 86.61% the size of Kaiserslautern.
Tip: This to-scale comparison of Kaiserslautern vs. San Francisco uses the Mercator projection, which distorts the size of regions near the poles.
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