To estimate the real measure of the GDP it muste be adjusted using real-time inflation, which is the interanual inflation, or equivalent to the Consumer Price Index. Using this it real GDP can be calculated and compared between years, quarters or semesters.
Real gross domestic product (GDP) is an inflation-adjusted measure that reflects the value of all goods and services produced by an economy in a given year, expressed in base-year prices, and is often referred to as "constant-price," "inflation-corrected" GDP or "constant dollar GDP."
