Belgium is about 8 times bigger than South Georgia and South Sandwich Islands.

South Georgia and South Sandwich Islands is approximately 3,903 sq km, while Belgium is approximately 30,528 sq km, making Belgium 682% larger than South Georgia and South Sandwich Islands.
Tip: This to-scale comparison of South Georgia and South Sandwich Islands vs. Belgium uses the Mercator projection, which distorts the size of regions near the poles.
Compare further: Belgium vs. South Georgia and South Sandwich Islands