British Indian Ocean Territory is about 289 times smaller than Swaziland.

Swaziland is approximately 17,364 sq km, while British Indian Ocean Territory is approximately 60 sq km, making British Indian Ocean Territory 0.35% the size of Swaziland. Meanwhile, the population of Swaziland is ~1.3 million people (1.3 million fewer people live in British Indian Ocean Territory).
Tip: This to-scale comparison of Swaziland 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. Swaziland

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