Hanoi is about 7 times bigger than Prague.

Prague is approximately 496 sq km, while Hanoi is approximately 3,360 sq km, making Hanoi 577% larger than Prague.
Tip: This to-scale comparison of Prague vs. Hanoi 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.