South Georgia and South Sandwich Islands is about 135 times smaller than Yemen.

Yemen is approximately 527,968 sq km, while South Georgia and South Sandwich Islands is approximately 3,903 sq km, making South Georgia and South Sandwich Islands 0.74% the size of Yemen.
Tip: This to-scale comparison of Yemen 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. Yemen