Rochester is about 4.7 times smaller than Montreal.

Montreal is approximately 432 sq km, while Rochester is approximately 93 sq km, making Rochester 21.47% the size of Montreal.
Tip: This to-scale comparison of Montreal vs. Rochester 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.