El Salvador is about 21 times smaller than Sweden.

Sweden is approximately 450,295 sq km, while El Salvador is approximately 21,041 sq km, making El Salvador 4.67% the size of Sweden. Meanwhile, the population of Sweden is ~10.5 million people (3.9 million fewer people live in El Salvador).
Tip: This to-scale comparison of Sweden vs. El Salvador uses the Mercator projection, which distorts the size of regions near the poles.