United States is 16 times larger than Madagascar.
Area: 587,041 km2 World Factbook
Population: 23,201,926 (July 2014) World Factbook
Madagascar, officially the Republic of Madagascar and previously known as the Malagasy Republic, is an island country in the Indian Ocean, off the coast of Southeast Africa. The nation comprises the island of Madagascar, as well as numerous smaller peripheral islands. Wikipedia
The United States of America, commonly referred to as the United States, America, and sometimes the States, is a federal republic consisting of 50 states and a federal district. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. Wikipedia