Montserrat is about 765 times smaller than South Carolina.

South Carolina is approximately 77,983 sq km, while Montserrat is approximately 102 sq km, making Montserrat 0.13% the size of South Carolina. Meanwhile, the population of South Carolina is ~4.6 million people (4.6 million fewer people live in Montserrat).
Tip: This to-scale comparison of South Carolina vs. Montserrat uses the Mercator projection, which distorts the size of regions near the poles.