New Caledonia is about 379 times bigger than Bouvet Island.

Bouvet Island is approximately 49 sq km, while New Caledonia is approximately 18,575 sq km, making New Caledonia 37,808% larger than Bouvet Island.
Tip: This to-scale comparison of Bouvet Island vs. New Caledonia uses the Mercator projection, which distorts the size of regions near the poles.