Santa Ana is about 18 times smaller than Rome.

Rome is approximately 1,287 sq km, while Santa Ana (map shows its 60 named neighbourhoods; the area covers the whole city) is approximately 71 sq km, making Santa Ana 5.51% the size of Rome.
Tip: This to-scale comparison of Rome vs. Santa Ana 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.