Rome is about 2.2 times smaller than Ottawa.

Ottawa is approximately 2,779 sq km, while Rome is approximately 1,287 sq km, making Rome 46.33% the size of Ottawa.
Tip: This to-scale comparison of Ottawa vs. Rome 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.