Tucson is about 11 times smaller than Ho Chi Minh City.

Ho Chi Minh City is approximately 6,773 sq km, while Tucson (map shows its 130 named neighbourhoods; the area covers the whole city) is approximately 627 sq km, making Tucson 9.26% the size of Ho Chi Minh City.
Tip: This to-scale comparison of Ho Chi Minh City vs. Tucson 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.