Athens is about 2.3 times smaller than Sao Tome and Principe.

Sao Tome and Principe is approximately 964 sq km, while Athens is approximately 412 sq km, making Athens 42.74% the size of Sao Tome and Principe.
Tip: This to-scale comparison of Sao Tome and Principe vs. Athens uses the Mercator projection, which distorts the size of regions near the poles.