The World Bank classifies countries in one four categories, depending upon level of economic development. Simply, the Bank categorizes countries as low, middle, upper-middle, and high-income, with gross domestic product being the determining number. Low-income countries, under World Bank criteria, are those with gross domestic products of $1,035 or less per annum. Middle-income countries have GNPs within the range of $1,036 to $4,085. Upper-middle-income economies are those with GNPs between $4,086 and $12,615, and high-income economies are those with GNPs above $12,616.
In addition to country rankings or categorizations according to wealth, the World Bank also groups countries according to geographic region: East Asia and the Pacific; Europe and Central Asia; Latin America and the Caribbean; Middle East and North Africa; South Asia, and Sub-Saharan Africa.