Gross domestic product is the monetary value of all the complete goods and services formed within a country’s margins in an exact time period, though gross domestic product is generally calculated on an annual source. It includes all of private and public expenditure, government outlays, investments and exports less imports that occur within a defined field. Formula to calculate, GDP = C + G + I + NX. Where: “C” is equal to all private expenditure, in a nation’s economy; “G” is the sum of government expenditure.