Barcelona is about 12 times smaller than Los Angeles.

Los Angeles (including the city proper only) is approximately 1,215 sq km, while Barcelona is approximately 101 sq km, making Barcelona 8.34% the size of Los Angeles.
Tip: This to-scale comparison of Los Angeles vs. Barcelona 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.