The primary factor used to distinguish developed countries from developing countries is the gross domestic product (GDP) per capita, a tally of all the goods and services produced in a country in one year, expressed in U.S. dollars. GDP is calculated by dividing a country's GDP by its population. For example, a small country with a GDP of $1 billion and a population of 50,000 has a GDP per capita of $20,000. One unofficial threshold for a country with a developed economy is a GDP per capita of $12,000. Some economists prefer to see a per capita GDP of at least $25,000 to be comfortable declaring a country as developed, however. Many highly developed countries, including the United States, have high per capita GDPs of $40,000 or above.
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