Dublin is about 8 times smaller than Sao Tome and Principe.

Sao Tome and Principe is approximately 964 sq km, while Dublin is approximately 118 sq km, making Dublin 12.22% the size of Sao Tome and Principe.
Tip: This to-scale comparison of Sao Tome and Principe vs. Dublin uses the Mercator projection, which distorts the size of regions near the poles.