According to the World Bank Gross Domestic Product (GDP) of World in 2015 was 73,502 Trillion USD. More than half (48.77 Trillion USD) of it was produced in the TOP 10 largest economies of the World. 

In this article we will figure out and name those TOP 10 economies, as well compare some historical data, but before that - there are different ways to calculate GDP. For the ease of this article I will cover details only about GDP nominal, although GDP PPP is another great way to measure actual purchasing power.

Nominal GDP is gross domestic product (GDP) evaluated at current market prices, GDP being the monetary value of all the finished goods and services produced within a country’s borders in a specific time period. Nominal differs from real GDP in that it includes changes in prices due to inflation or a rise in the overall price level.

I started cover articles on the World's top economies back in 2013, back then compared economies of 2012, a year latter about 2013. Unfortunately I have skipped article about 2014. It's always cool to compare, again for the ease of this article I will compare data from 2012 to 2015. Let me assure, there are few surprises (at least for me).

For my simple calculations I'm using data provided from different sources, World Bank and International Monetary Fund being a top of them. World Bank has been my favorite source, probably because their site has been built on Drupal

Now, back to the topic:

Top 10 Largest Economies In The World by GDP Nominal (2015)

Rank Country 2015 T $ 2012 T % Growth bln $  Growth %  
1 United States 17,946 16,155 1,791 11.08%  
2 China 10,866 8,461 2,405 28.42%  
3 Japan 4,123 5,957 -1,834 -30.78%  
4 Germany 3,355 3,539 -184 -5.19%  
5 United Kingdom 2,848 2,630 218 8.28%  
6 France 2,421 2,681 -260 -9.69%  
7 India 2,073 1,824 249 13.65%  
8 Italy 1,814 2,072 -258 -12.45%  
9 Brazil 1,774 2,460 -686 -27.88%  
10 Canada 1,550 1,824 -274 -15.02%  
  Total 48,770 47,603 1,167 2.45%  

Data source: World Bank

Let's start with the obvious - most countries, except United States, China, United Kingdom and India have lost some (I would even say, pretty serious) value of GDP in 2015, if compared to 2012. Nope, China is still second (although it's believed that China have over passed United States in terms of GDP PPP already in 2014). There is one country which have left the TOP 10 in 2015, and one country which have replaced it. Russia, ranked 8th in 2012, ranks 13 in 2015. Canada ranked 11th in 2012, replaced Russia in 2015, ranking as the 10th.

India have shifted places with Italy. Making India my biggest surprise of this list.

#1 United States

The United States is the world's largest national economy in nominal terms and second largest according to purchasing power parity (PPP), representing 22% of nominal global GDP and 17% of gross world product (GWP). The United States' GDP was estimated to be $17.914 trillion as of Q2 2015. The U.S. dollar is the currency most used in international transactions and is the world's foremost reserve currency, backed by its science and technology, its military, the full faith of the US government to reimburse its debts, its central role in a range of international institutions since World War II and the petrodollar system. Several countries use it as their official currency, and in many others it is the de facto currency. The United States has a mixed economy and has maintained a stable overall GDP growth rate, a moderate unemployment rate, and high levels of research and capital investment. Its seven largest trading partners are Canada, China, Mexico, Japan, Germany, South Korea, and the United Kingdom.

#2 China

China's socialist market economy is the world's second largest economy by nominal GDP, and the world's largest economy by purchasing power parity according to the IMF, although China's National Bureau of Statistics rejects this claim. Until 2015 China was the world's fastest-growing major economy, with growth rates averaging 10% over 30 years. Due to historical and political facts of China's developing economy, China's public sector accounts for a bigger share of the national economy than the burgeoning private sector.

China is a global hub for manufacturing, and is the largest manufacturing economy in the world as well as the largest exporter of goods in the world. China is also the world's fastest growing consumer market and second largest importer of goods in the world. China is a net importer of services products.

#3 Japan

The economy of Japan is the third-largest in the world by nominal GDP and the fourth-largest by purchasing power parity (PPP). and is the world's second largest developed economy.According to the International Monetary Fund, the country's per capita GDP (PPP) was at $37,519, the 28th highest in 2014, down from the 22nd position in 2012. Japan is a member of the G7. Due to a volatile currency exchange rate, Japan's GDP as measured in dollars fluctuates widely. Accounting for these fluctuations through use of the Atlas method, Japan is estimated to have a GDP per capita of around $38,490.

#4 Germany

Germany is the largest national economy in Europe, the fourth-largest by nominal GDP in the world, and fifth by GDP (PPP). The country is a founding member of the European Union and the Eurozone. The economic model of Germany is based on the concept of the social market economy.

In 2014, Germany recorded the highest trade surplus in the world worth $285 billion, making it the biggest capital exporter globally. Germany is the third largest exporter in the world with 1.13 trillion euros ($1.28 trillion) in goods and services exported in 2014. The service sector contributes around 70% of the total GDP, industry 29.1%, and agriculture 0.9%. Exports account for 41% of national output. The top 10 exports of Germany are vehicles, machineries, chemical goods, electronic products, electrical equipments, pharmaceuticals, transport equipments, basic metals, food products, and rubber and plastics.

#5 United Kingdom

The economy of the United Kingdom is the fifth-largest national economy in the world measured by nominal gross domestic product (GDP) and ninth-largest in the world measured by purchasing power parity (PPP), comprising 4% of world GDP; it is the second-largest economy in the European Union by both metrics.

In 2015, the UK was the ninth-largest exporter in the world and the sixth-largest importer, and it had the second-largest stocks of inward foreign direct investment and outward foreign direct investment. It is one of the most globalised economies, and is composed of (in descending order of size) the economies of England, Scotland, Wales and Northern Ireland.

The service sector dominates the UK economy, contributing around 78% of GDP; the financial services industry is particularly important, and London is the world's largest financial centre. Britain's aerospace industry is the second- or third-largest national aerospace industry depending on the method of measurement. Its pharmaceutical industry plays an important role in the economy and the UK has the third-highest share of global pharmaceutical research and development. Of the world's 500 largest companies, 26 are headquartered in the UK. The British economy is boosted by North Sea oil and gas production; its reserves were estimated at 2.9 billion barrels in 2015, although it has been a net importer of oil since 2005. There are significant regional variations in prosperity, with South East England and southern Scotland being the richest areas per capita. The size of London's economy makes it the largest city by GDP in Europe.

#6 France

The chemical industry is a key sector for France, helping to develop other manufacturing activities and contributing to economic growth. France's tourism industry is a major component of the economy, as France is the most visited destination in the world. Sophia Antipolis is the major technology hub for the economy of France. According to the IMF, in 2013, France was the world's 20th country by GDP per capita with $44,099 per inhabitant. In 2013, France was listed on the United Nations's Human Development Index with 0.884 (very high human development) and 25th on the Corruption Perceptions Index.

France's economy entered the recession of the late 2000s later and appeared to leave it earlier than most affected economies, only enduring four-quarters of contraction.However, France experienced stagnant growth between 2012 and 2014, with the economy expanding by 0% in 2012, 0.8% in 2013 and 0.2% in 2014, though growth picked up in 2015 with a growth of 1.2% and a forecasted growth of 1.5% for 2016, and 1.7% for 2017.The highest since 2011 (2.1%).

#7 India

The economy of India is the seventh-largest economy in the world measured by nominal GDP and the third-largest by purchasing power parity (PPP).  The country is classified as a newly industrialised country, one of the G-20 major economies, a member of BRICS and a developing economy with an average growth rate of approximately 7% over the last two decades. Maharashtra is the wealthiest Indian state and has an annual nominal GDP of US$250 billion, nearly equal to that of Portugal and Pakistan and accounts for 12% of the Indian GDP followed by the states of Tamil Nadu (US$150 billion) and Uttar Pradesh (US$130 billion). India's economy became the world's fastest growing major economy in the last quarter of 2014, replacing the People's Republic of China.

The long-term growth prospective of the Indian economy is positive due to its young population, corresponding low dependency ratio, healthy savings  and investment rates, and increasing integration into the global economy. The Indian economy has the potential to become the world's 3rd-largest economy by the next decade, and one of the two largest economies by mid-century. And the outlook for short-term growth is also good as according to the IMF, the Indian economy is the "bright spot" in the global landscape. India also topped the World Bank’s growth outlook for 2015-16 for the first time with the economy having grown 7.6% in 2015-16 and expected to grow 8.0%+ in 2016-17.

#8 Italy

Italy is the 3rd-largest national economy in the Euro Zone, the 8th-largest by nominal GDP in the world, and the 12th-largest by GDP (PPP). The country is a founding member of the European Union, the Eurozone, the OECD, the G7 and the G8. Italy is the eighth largest exporter in the world with $514 billion exported in 2016. Its closest trade ties are with the other countries of the European Union, with whom it conducts about 59% of its total trade. The largest trading partners, in order of market share, are Germany (12.6%), France (11.1%), United States (6.8%), Switzerland (5.7%), United Kingdom (4.7%), and Spain (4.4%).

In the post-war period, Italy was transformed from an agricultural based economy which had been severely affected by the consequences of the World Wars, into one of the world's most industrialized nations, and a leading country in world trade and exports. According to the Human Development Index, the country enjoys a very high standard of living, and has the world's 8th highest quality of life according to The Economist. Italy owns the world's third-largest gold reserve, and is the third net contributor to the budget of the European Union. The country is also well known for its influential and innovative business economic sector, an industrious (Italy is the second largest manufacturer in Europe behind Germany) and competitive agricultural sector (Italy is the world's largest wine producer), and for its creative and high-quality automobile, naval, industrial, appliance and fashion design. Italy is the largest market for luxury goods in Europe (third in the world).

#9 Brazil

Brazil has the world's ninth largest economy by nominal GDP, and the fifth largest by purchasing power parity. The Brazilian economy is characterized by moderately free markets and an inward-oriented economy.

Brazil's economy is the largest of Latin America and the second largest in the Americas. From 2000 to 2012, Brazil was one of the fastest-growing major economies in the world, with an average annual GDP growth rate of over 5%, with its economy in 2012 surpassing that of the United Kingdom, temporarily making Brazil the world's sixth largest economy. However, Brazil's economy growth decelerated in 2013 and the country entered an ongoing recession in 2014.

#10 Canada

Canada has the 10th (nominal) or 15th-largest (PPP) economy in the world (measured in US dollars at market exchange rates), is one of the world's wealthiest nations, and is a member of the Organization for Economic Co-operation and Development (OECD) and Group of Seven (G7). As with other developed nations, the Canadian economy is dominated by the service industry, which employs about three quarters of Canadians. Canada is unusual among developed countries in the importance of the primary sector, with the logging and oil industries being two of Canada's most important. Canada also has a sizable manufacturing sector, based in Central Canada, with the automobile industry and aircraft industry being especially important. With a long coastline, Canada has the 8th largest commercial fishing and seafood industry in the world. Canada is one of the global leaders of the entertainment software industry.

India is the country to watch for.