There are many ways to rank the word's most powerful companies. Looking at market value, brand value or sales revenue are all methods used to rank the biggest companies in the world.

From the data, it is apparent that the most powerful companies are mostly based in the U.S., followed by China and then Europe. Companies in the oil & gas sector are the most valuable in aggregate, followed by technology and financial services & banking.

Largest Companies on U.S. Exchanges by Market Capitalization

The market capitalization of a company is a measure of its value, and therefore its size and influence. Market capitalization is measured by multiplying the share price of a company's stock by the number of shares outstanding.

The largest 20 companies traded on American stock exchanges are:

Rank Company Name Ticker Industry Market Cap ($USD billions)
1 Apple Inc. AAPL Computers, hardware 674.46
2 Microsoft Corp.* MSFT Computers, software 399.12
3 Exxon Mobil* XOM Oil and gas 397.28
4 Berkshire Hathaway BKR.B Diversified 371.01
5 Google Inc. GOOGL Software, internet 357.27
6 Johnson & Johnson JNJ Pharmaceuticals, Consumer Products 303.73
7 PetroChina (ADR) PTR Oil and gas 289.79
8 Wells Fargo & Co. WFC Finance, banks 285.48
9 Walmart Stores* WMT Retail 271.13
10 Alibaba Group (ADR) BABA Internet 268.21
11 Novartis AG (ADR) NVS Pharmaceuticals 261.37
12 General Electric* GE Diversified manufacturing 261.21
13 Roche Holdings (ADR) RHHBY:OTC Pharmaceuticals 261.37
14 China Mobile (ADR) CHL Telecommunications 250.12
15 Proctor & Gamble Co.* PG Consumer products 244.22
16 Nestle SA (ADR) NSRGF:OTC Food and beverage 240.87
17 JPMorgan Chase & Co. JPM Finance, banking 234.38
18 Toyota Motors (ADR) TM Automobiles 217.11
19 Royal Dutch Shell (ADR) RDS.A Oil and gas 217.11
20 Facebook Inc. FB Internet, social media 212.88

Source: Google Finance, data as of 12/5/2014

* indicates a member of the Dow Jones Industrial Average (DJIA)

'ADR' indicates an American Depository Receipt, or foreign company traded on American stock exchanges.

The Forbes Index of Most Powerful Brands

A strong brand name is a very valuable asset. Forbes sets out to rank companies by their brand awareness and the power that those brands carry. While there is some overlap with the most valuable companies by market capitalization, there are also many differences.

Rank Company Name Ticker Industry Brand Value ($USD billions)
1 Apple Inc. AAPL Computers, hardware 124.2
2 Microsoft Corp.* MSFT Computers, software 63
3 Google Inc. GOOGL Software, internet 56.6
4 Coca Cola* KO Food and beverage 56.1
5 IBM* IBM Technology 47.9
6 MacDonald's* MCD Restaurants 39.9
7 General Electric GE Diversified manufacturing 37.1
8 Samsung Electronics N/A Consumer goods, electronics 35
9 Toyota Motors (ADR) TM Automobiles 31.3
10 Louis Vuitton (ADR) LVMUY:OTC Luxury goods, fashion 29.9
11 BMW N/A Automobiles 28.8
12 Cisco Systems* CSCO Computer hardware, Networking 28
13 Intel* INTC Semiconductors 28
14 Disney* DIS Entertainment 27.4
15 Oracle ORCL Software 25.8
16 AT&T T Telecommunications 24.9
17 Mercedes Benz N/A Automobiles 23.8
18 Facebook Inc. FB Internet, social media 23.7
19 Walmart Stores* WMT Retail 23.3
20 Honda Motors (ADR) HMC Automobiles

23.2

Source: FactSet, Forbes.com

* indicates a member of the Dow Jones Industrial Average (DJIA)

'ADR' indicates an American Depository Receipt, or foreign company traded on American stock exchanges.

World's Largest Companies by Sales Revenue

A third way to rank the largest and most powerful companies is by using sales revenue as a measure of size: 

Rank Company Name Ticker Industry Revenue ($USD billions)
1 Walmart Stores* WMT Retail 476
2 Sinopec Group (ADR) SHI Oil and gas 475
3 China National Petroleum N/A Oil and gas 455
4 Royal Dutch Shell (ADR) RDS.A Oil and gas 451
5 Exxon Mobile* XOM Oil and gas 420
6 British Petroleum (ADR) BP Oil and gas 379
7 Saudi Aramco N/A Oil and gas 365
8 State Grid Corp. of China N/A Utilities, electricity 338
9 Vitol N/A Minerals and mining 307
10 Volkswagen Group (ADR) VLKAY:OTC Automobiles 263
11 Total SA (ADR) TOT Oil and gas 253
12 Toyota Motors (ADR) TM Automobiles 249
13 Glencore Xstrata N/A Minerals and mining 239
14 Chevron Corp* CVX Oil and gas 220
15 Samsung Electronics N/A Consumer goods, electronics 216
16 Apple Inc. AAPL Computers, hardware 182
17 Berkshire Hathaway BKR.B Diversified 182
18 China Railway Corp. N/A Transportation 172
19 Philips 66 PSX Oil and gas 171
20 E.ON (ADR) EONGY:OTC Utilities, electricity 163

Source: Wikipedia.com. Data as of 12/31/2013.

* indicates a member of the Dow Jones Industrial Average (DJIA)

'ADR' indicates an American Depository Receipt, or foreign company traded on American stock exchanges.

The Bottom Line

Depending on which methodology you use to rank the world's biggest and most powerful companies, the list will be different. There is a bit of overlap however, and some trends can be identified.

Chinese companies are rapidly gaining value and influence. The oil and gas industry remains a dominant force in the world economy, even though the brand values of oil and gas companies don't rank very highly. Consumer-facing companies such as Coca Cola and Disney that do not make the top 20 in market capitalization or revenues do rank highly in brand value.