Potsdam is about 1.6 times bigger than San Francisco.

San Francisco (including the city proper only) is approximately 121 sq km, while Potsdam is approximately 188 sq km, making Potsdam 56% larger than San Francisco.
Tip: This to-scale comparison of San Francisco vs. Potsdam uses the Mercator projection, which distorts the size of regions near the poles.
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