GDP is the total market value of all final goods and services produced within a country's borders in a period of time. It includes private consumption, investment, government spending, and net exports. GDP is calculated as C + I + G + (X - M), where C is consumption, I is investment, G is government spending, X is exports, and M is imports. NDP is GDP minus depreciation on capital goods used in production. GNP is the total value of final goods and services produced by a country's residents, wherever located. It includes income earned abroad but excludes income earned domestically by foreign residents. NNP is GNP minus depreciation on capital goods.