Denver is about 3.2 times smaller than Rome.

Rome is approximately 1,287 sq km, while Denver is approximately 396 sq km, making Denver 30.8% the size of Rome.
Tip: This to-scale comparison of Rome vs. Denver 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.