San Bernardino is about 6 times smaller than Berlin.

Berlin is approximately 891 sq km, while San Bernardino (map shows its 50 named neighbourhoods; the area covers the whole city) is approximately 161 sq km, making San Bernardino 18.05% the size of Berlin.
Tip: This to-scale comparison of Berlin vs. San Bernardino uses the Mercator projection, which distorts the size of regions near the poles.
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