South Georgia and South Sandwich Islands is about 17 times smaller than Sri Lanka.

Sri Lanka is approximately 65,610 sq km, while South Georgia and South Sandwich Islands is approximately 3,903 sq km, making South Georgia and South Sandwich Islands 5.95% the size of Sri Lanka.
Tip: This to-scale comparison of Sri Lanka 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. Sri Lanka