What is GDP?

Gross Domestic Product (GDP) is the total market value of all final goods and services produced within a country's borders during a specific time period, typically measured quarterly and annualized. It is the most comprehensive single measure of economic activity and the standard yardstick for comparing the size and growth of economies worldwide.

GDP can be calculated through three equivalent approaches: the expenditure approach (adding up consumption, investment, government spending, and net exports), the income approach (adding up all incomes earned in production), and the production approach (adding up the value added at each stage of production). The expenditure approach is most commonly cited, where GDP = C + I + G + (X - M). Consumer spending (C) accounts for roughly 70% of US GDP, making household demand the dominant driver of the US economy.

The distinction between nominal and real GDP is critical. Nominal GDP measures output at current prices, so it can increase either because more goods are produced or because prices rose (inflation). Real GDP adjusts for inflation using a base-year price level, isolating the actual change in economic output. When economists and the media discuss GDP growth, they almost always mean real GDP growth.

GDP data is released in three stages: the advance estimate (about one month after the quarter ends), the second estimate (two months after), and the third estimate (three months after). Each release incorporates more complete data and can revise the previous estimate significantly. The advance estimate is the most market-moving. The Atlanta Fed's GDPNow model provides a real-time running estimate of GDP growth during the current quarter, which is widely followed between official releases.

Two consecutive quarters of negative real GDP growth is the common shorthand definition of a recession, although the official determination is made by the NBER Business Cycle Dating Committee using a broader set of criteria. For investors and policymakers, GDP growth is a key input into corporate earnings expectations, tax revenue projections, and monetary policy decisions. Understanding GDP trends provides the foundational context for interpreting nearly every other economic and market indicator.