United States: Population and Key Statistics

With a GDP of 29.2 trillion dollars, the United States is the world's largest economy and accounts for roughly a quarter of global economic output on its own. Home to 345 million people, making it the third most populous country in the world, the United States leads globally in technology, finance, defense, and entertainment, and hosts most of the world's most valuable companies.

The U.S. dollar retains its status as the global reserve currency, while the country ranks at the top in research and development spending and in university rankings. As a nation of immigrants, the United States owes much of its population growth to immigration, which helps it maintain a relatively young age structure (median age 38.3) among advanced economies.