Bouvet Island is about 1.2 times smaller than British Indian Ocean Territory.

British Indian Ocean Territory is approximately 60 sq km, while Bouvet Island is approximately 49 sq km, making Bouvet Island 81.67% the size of British Indian Ocean Territory.
Tip: This to-scale comparison of British Indian Ocean Territory vs. Bouvet Island uses the Mercator projection, which distorts the size of regions near the poles.

Compare further: Bouvet Island vs. British Indian Ocean Territory