San Francisco is around the same size as Bronx.

Bronx is approximately 109 sq km, while San Francisco (including the city proper only) is approximately 121 sq km, making San Francisco 11% larger than Bronx.
Tip: This to-scale comparison of Bronx vs. San Francisco uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.