Tuvalu is about 1.9 times smaller than Bouvet Island.

Bouvet Island is approximately 49 sq km, while Tuvalu is approximately 26 sq km, making Tuvalu 53.06% the size of Bouvet Island.
Tip: This to-scale comparison of Bouvet Island vs. Tuvalu uses the Mercator projection, which distorts the size of regions near the poles.