El Salvador is about 61 times bigger than Grenada.

Grenada is approximately 344 sq km, while El Salvador is approximately 21,041 sq km, making El Salvador 6,017% larger than Grenada. Meanwhile, the population of Grenada is ~113,949 people (6.5 million more people live in El Salvador).
Tip: This to-scale comparison of Grenada vs. El Salvador uses the Mercator projection, which distorts the size of regions near the poles.