Fargo is about 25 times smaller than Hanoi.

Hanoi is approximately 3,360 sq km, while Fargo (map shows its 38 named neighbourhoods; the area covers the whole city) is approximately 133 sq km, making Fargo 3.97% the size of Hanoi.
Tip: This to-scale comparison of Hanoi vs. Fargo 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.