Vietnam is about 1.4 times bigger than United Kingdom.

United Kingdom is approximately 243,610 sq km, while Vietnam is approximately 331,210 sq km, making Vietnam 36% larger than United Kingdom. Meanwhile, the population of United Kingdom is ~69.5 million people (32.1 million more people live in Vietnam).
Tip: This to-scale comparison of United Kingdom vs. Vietnam uses the Mercator projection, which distorts the size of regions near the poles.
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