Vietnam is about 6 times smaller than Indonesia.

Indonesia is approximately 1,904,569 sq km, while Vietnam is approximately 331,210 sq km, making Vietnam 17.39% the size of Indonesia. Meanwhile, the population of Indonesia is ~285.7 million people (184.1 million fewer people live in Vietnam).
Tip: This to-scale comparison of Indonesia vs. Vietnam uses the Mercator projection, which distorts the size of regions near the poles.
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