The Gross Domestic Product (GDP) at market price is derived by using the GDP(E) formula, which is the sum of the value of all final goods and services produced in a given period of time. This includes the value of all goods and services produced by both the public and private sectors, including government spending, investment, and exports. The GDP(E) formula is used to calculate the total value of all goods and services produced in a given period of time, and is used to measure the size of an economy.