Belgium is 500 times larger than San Marino.
Area: 30,528 km2 World Factbook
Population: 10,449,361 (July 2014) World Factbook
Belgium, officially the Kingdom of Belgium, is a federal monarchy in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters as well as those of several other major international organisations such as NATO. 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