Comparing GDP among Countries

Converting Currencies with Exchange Rates

To compare the GDP of countries with different currencies, it is necessary to convert to a “common denominator” using an exchange rate, which is the value of one currency in terms of another currency. We express exchange rates either as the units of country A’s currency that need to be traded for a single unit of country B’s currency (for example, Japanese yen per British pound), or as the inverse (for example, British pounds per Japanese yen). We can use two types of exchange rates for this purpose, market exchange rates and purchasing power parity (PPP) equivalent exchange rates. Market exchange rates vary on a day-to-day basis depending on supply and demand in foreign exchange markets. PPP-equivalent exchange rates provide a longer run measure of the exchange rate. For this reason, economists typically use PPP-equivalent exchange rates for GDP cross country comparisons. We will discuss exchange rates in more detail in Exchange Rates and International Capital Flows. The following Work It Out feature explains how to convert GDP to a common currency.

Converting GDP to a Common Currency

Using the exchange rate to convert GDP from one currency to another is straightforward. Say that the task is to compare Brazil’s GDP in 2013 of 4.8 trillion reals with the U.S. GDP of $16.6 trillion for the same year.

Step 1. Determine the exchange rate for the specified year. In 2013, the exchange rate was 2.230 reals = $1. (These numbers are realistic, but rounded off to simplify the calculations.)

Step 2. Convert Brazil’s GDP into U.S. dollars:

Brazil's GDP in $ U.S. = Brazil's GDP in realsExchange rate (reals/$ U.S.) = 4.8 trillion reals2.230 reals per $ U.S. = $2.2 trillion

Step 3. Compare this value to the GDP in the United States in the same year. The U.S. GDP was $16.6 trillion in 2013, which is nearly eight times that of GDP in Brazil in 2012.

Step 4. View Table which shows the size of and variety of GDPs of different countries in 2013, all expressed in U.S. dollars. We calculate each using the process that we explained above.

Country GDP in Billions of Domestic Currency Domestic Currency/U.S. Dollars (PPP Equivalent) GDP (in billions of U.S. dollars)
Brazil 4,844.80 reals 2.157 2,246.00
Canada 1,881.20 dollars 1.030 1,826.80
China 58,667.30 yuan 6.196 9,469.10
Egypt 1,753.30 pounds 6.460 271.40
Germany 2,737.60 euros 0.753 3,636.00
India 113,550.70 rupees 60.502 1,876.80
Japan 478,075.30 yen 97.596 4,898.50
Mexico 16,104.40 pesos 12.772 1,260.90
South Korea 1,428,294.70 won 1,094.925 1,304.467
United Kingdom 1,612.80 pounds 0.639 2,523.20
United States 16,768.10 dollars 1.000 16,768.10
Comparing GDPs Across Countries, 2013 (Source: http://www.imf.org/external/pubs/ft/weo/2013/01/weodata/index.aspx)