Seattle is about 2 times smaller than Montreal.

Montreal is approximately 432 sq km, while Seattle is approximately 217 sq km, making Seattle 50.36% the size of Montreal.
Tip: This to-scale comparison of Montreal vs. Seattle 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.