Guam is about 2.1 times bigger than Niue.

Niue is approximately 260 sq km, while Guam is approximately 544 sq km, making Guam 109% larger than Niue. Meanwhile, the population of Niue is ~1,933 people (167,066 more people live in Guam).
Tip: This to-scale comparison of Niue vs. Guam uses the Mercator projection, which distorts the size of regions near the poles.
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