El Salvador is 345 times larger than San Marino.
Area: 21,041 km2 World Factbook
Population: 6,125,512 (July 2014) World Factbook
El Salvador, officially the Republic of El Salvador, is the smallest and the most densely populated country in Central America. The country's capital city and largest city is San Salvador. Important cultural and commercial centers for Central America on the whole include Santa Ana and San Miguel. Wikipedia
Area: 61 km2 World Factbook
Population: 32,742 (July 2014) World Factbook
San Marino, officially the Republic of San Marino and also known as the Most Serene Republic of San Marino, is an enclaved microstate surrounded by Italy, situated on the Italian Peninsula on the north-eastern side of the Apennine Mountains. Wikipedia