Mississippi is about 126 times bigger than Sao Tome and Principe.

Sao Tome and Principe is approximately 964 sq km, while Mississippi is approximately 121,489 sq km, making Mississippi 12,503% larger than Sao Tome and Principe. Meanwhile, the population of Sao Tome and Principe is ~217,164 people (2.8 million more people live in Mississippi).
Tip: This to-scale comparison of Sao Tome and Principe vs. Mississippi uses the Mercator projection, which distorts the size of regions near the poles.