Colorado is about 1.2 times smaller than Vietnam.

Vietnam is approximately 331,210 sq km, while Colorado is approximately 268,627 sq km, making Colorado 81.1% the size of Vietnam. Meanwhile, the population of Vietnam is ~101.6 million people (95.6 million fewer people live in Colorado).
Tip: This to-scale comparison of Vietnam vs. Colorado 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.