The United States of America is being the top country by GDP in the world. As of 2015, GDP in the United States of America was 18,036,648 million current US$ that accounts for 24.88 % of the world's GDP. The top 5 countries (others are China, Japan, Germany, and the United Kingdom) account for 54.69 % of it. The world's total GDP was estimated at 72,497,189 million current US$ in 2015.
GDP at purchaser's prices is the sum of gross value added by all resident producers in the economy plus any product taxes and minus any subsidies not included in the value of the products. It is calculated without making deductions for depreciation of fabricated assets or for depletion and degradation of natural resources. Data are in current U.S. dollars. Dollar figures for GDP are converted from domestic currencies using single year official exchange rates. For a few countries where the official exchange rate does not reflect the rate effectively applied to actual foreign exchange transactions, an alternative conversion factor is used.