French Southern and Antarctic Lands is about 17 times bigger than Northern Mariana Islands.

Northern Mariana Islands is approximately 464 sq km, while French Southern and Antarctic Lands is approximately 7,829 sq km, making French Southern and Antarctic Lands 1,587% larger than Northern Mariana Islands.
Tip: This to-scale comparison of Northern Mariana Islands vs. French Southern and Antarctic Lands uses the Mercator projection, which distorts the size of regions near the poles.
Compare further: French Southern and Antarctic Lands vs. Northern Mariana Islands