Oman is about 40 times bigger than French Southern and Antarctic Lands.

French Southern and Antarctic Lands is approximately 7,829 sq km, while Oman is approximately 309,500 sq km, making Oman 3,853% larger than French Southern and Antarctic Lands.
Tip: This to-scale comparison of French Southern and Antarctic Lands vs. Oman uses the Mercator projection, which distorts the size of regions near the poles.
Compare further: Oman vs. French Southern and Antarctic Lands