British Indian Ocean Territory is about 1.7 times smaller than Montserrat.

Montserrat is approximately 102 sq km, while British Indian Ocean Territory is approximately 60 sq km, making British Indian Ocean Territory 58.82% the size of Montserrat. Meanwhile, the population of Montserrat is ~5,440 people (2,440 fewer people live in British Indian Ocean Territory).
Tip: This to-scale comparison of Montserrat vs. British Indian Ocean Territory uses the Mercator projection, which distorts the size of regions near the poles.

Compare further: British Indian Ocean Territory vs. Montserrat

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