Western Sahara is about 1.2 times smaller than Oman.

Oman is approximately 309,500 sq km, while Western Sahara is approximately 266,000 sq km, making Western Sahara 85.95% the size of Oman. Meanwhile, the population of Oman is ~5.5 million people (4.9 million fewer people live in Western Sahara).
Tip: This to-scale comparison of Oman vs. Western Sahara uses the Mercator projection, which distorts the size of regions near the poles.
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