Stockholm is about 1.4 times smaller than Geneva.

Geneva (including the canton) is approximately 282 sq km, while Stockholm (map shows its 47 named neighbourhoods; the area covers the whole city) is approximately 207 sq km, making Stockholm 73.56% the size of Geneva.
Tip: This to-scale comparison of Geneva vs. Stockholm uses the Mercator projection, which distorts the size of regions near the poles.
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