Oman is about 2.6 times bigger than Eritrea.

Eritrea is approximately 117,600 sq km, while Oman is approximately 309,500 sq km, making Oman 163% larger than Eritrea. Meanwhile, the population of Eritrea is ~3.6 million people (1.9 million more people live in Oman).
Tip: This to-scale comparison of Eritrea vs. Oman uses the Mercator projection, which distorts the size of regions near the poles.
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