Gross domestic product (GDP) is a measure of the market value of final goods and services produced within the borders of a country during a specific time period, usually a year. What is the GDP deflator? How does the GDP deflator relate to real GDP? Review GDP and nominal versus real. Real adjusts for inflation, so how do we arrive at the real GDP number from nominal GDP? Review the GDP deflator formula, where GDP deflator = (Nominal GDP/Real GDP) X 100