Japan is 18 times larger than El Salvador.
Area: 377,915 km2 World Factbook
Population: 127,103,388 (July 2014) World Factbook
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. Wikipedia
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