Montreal is about 5 times bigger than The Hague (Den Haag).

The Hague (Den Haag) (excluding the city's 15.68 sq km of water area) is approximately 82 sq km, while Montreal is approximately 432 sq km, making Montreal 423% larger than The Hague (Den Haag).
Tip: This to-scale comparison of The Hague (Den Haag) vs. Montreal uses the Mercator projection, which distorts the size of regions near the poles.