Montreal is about 2 times bigger than Seattle.

Seattle is approximately 217 sq km, while Montreal is approximately 432 sq km, making Montreal 99% larger than Seattle.
Tip: This to-scale comparison of Seattle vs. Montreal 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.