South Georgia and South Sandwich Islands is about 28 times smaller than Cuba.

Cuba is approximately 110,860 sq km, while South Georgia and South Sandwich Islands is approximately 3,903 sq km, making South Georgia and South Sandwich Islands 3.52% the size of Cuba.
Tip: This to-scale comparison of Cuba vs. South Georgia and South Sandwich Islands uses the Mercator projection, which distorts the size of regions near the poles.
Compare further: South Georgia and South Sandwich Islands vs. Cuba