The 10 countries with the highest nominal gross domestic product as of 2015 are (ranked first to 10th) the United States, China, Japan, Germany, the United Kingdom, France, Brazil, Italy, India and Russia. There are no definitive numbers on what countries are spending, so organizations work with estimates to compose lists such as this.
Despite organizations all having their own ways of estimating gross domestic product, the top 10 listed here is identical for several of the most recognized organizations. The list features some non-countries as well, including the European Union, which would be number one if it was one country. Gross domestic product is often described as the amount of money a country spends, and thus, the most common definition for the economic power of a country; however, there are other ways to measure a country's economic power.
One other way is to measure the gross domestic product per capita. This list takes into account how many people live in a country. One could call countries on the top of this list richer because, despite spending less money in total, residents spend more money than in other countries. The top 10 countries listed by gross domestic product per capita are Qatar, Luxembourg, Singapore, Brunei, Kuwait, Norway, the United Arab Emirates, San Marino, Switzerland and the United States. This is according to a study done by the International Monetary Fund.