Papua New Guinea is about 1.4 times bigger than Vietnam.

Vietnam is approximately 331,210 sq km, while Papua New Guinea is approximately 462,840 sq km, making Papua New Guinea 40% larger than Vietnam. Meanwhile, the population of Vietnam is ~103.8 million people (94.2 million fewer people live in Papua New Guinea).
Tip: This to-scale comparison of Vietnam vs. Papua New Guinea uses the Mercator projection, which distorts the size of regions near the poles.
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