What is the largest airline in the world?

What is the largest airline in the world? The answer, of course, is not as simple as it may seem because it depends on how you measure it. Here are the rankings, broken down by different criteria

Passengers Per Year

The first way of judging which airline is the largest in the world is to go by the total amount of passengers carried in one year. US-based operators dominate the lineup with the top four in the world being headquartered in the country. American Airlines Group - which includes American Airlines Shuttle, American Eagle, Envoy Air, Piedmont Airlines, PSA Airlines - is the standout winner with 215 million passengers carried last year.

American Airlines Group
American Airlines Group carried more than 215 million passengers in 2019. Aviation Image Network/Simon Gregory

Chinese firms also feature prominently on the list with three airlines placing sixth, seventh and tenth. Irish low-cost carrier Ryanair is the highest-ranked non-US company in fifth place with 152.4 million passengers in 2019.

Passengers Carried Per Year
Rank Airline Country 2019
1 American Airlines Group US 215m
2 Delta Air Lines US 204m
3 Southwest Airlines US 162.7m
4 United Airlines US 162.4m
5 Ryanair Ireland 152.4m
6 China Southern Airlines China 151.6m
7 Lufthansa Group Germany 145m
8 China Eastern Airlines China 121.1m*
9 IAG UK 118m
10 Air China Group China 115m
*2018 figures

 

Fleet Size

The scale of an airline's roster is usually proportional to the number of passengers it flies, this is why the rankings are fairly similar to the previous table. The top four carriers are the same but just in a slightly different order.

Skywest
SkyWest operates flights on behalf of United Airlines for its 'Express' regional subsidiary. Aviation Image Network/Simon Gregory

SkyWest is a notable addition to the list as it is responsible for operating regional flights through contracts with major US carriers such as American Airlines, United and Delta.

Fleet Size
Rank Airline Country Fleet
1 American Airlines US 957
2 Delta Air Lines US 880
3 United Airlines US 777
4 Southwest Airlines US 753
5 China Eastern Airlines China 607
6 China Southern Airlines China 603
7 SkyWest US 486
8 Ryanair Ireland 456
9 Air China China 439
10 FedEx Express US 378

Number of Routes

For this measurement, the ranking has changed significantly and now includes different types of carriers. The addition of easyJet and Wizz Air indicates that even though they may not have large fleets by American Airlines' standards, they still operate a great number of routes.

easyJet
EasyJet is ranked fourth in the world by the number of routes it serves. Aviation Image Network/Simon Gregory

The list is focused on the number of routes each airline flew in the summer season of last year.

Number of Routes
Rank Airline Country Routes Served
1 Ryanair Ireland 1,831
2 American Airlines US 1,106
3 United Airlines US 950
4 easyJet UK 945
5 Delta Air Lines US 939
6 Southwest Airlines US 754
7 China Southern Airlines China 667
8 China Eastern Airlines China 648
9 Wizz Air Hungary 615
10 TUI Airways UK 470

Scheduled Passenger-Kilometres Flown 

A passenger-kilometre is an International Air Transport Association (IATA) term which is defined as being a unit of measure representing the movement of a single passenger in an aircraft over one kilometre.

Emirates A380
Emirates' average sector length and the capacity of each flight goes some way to explaining its presence at fourth-place on the list. Aviation Image Network/Simon Gregory

To obtain the figure, the total capacity of the aircraft is multiplied by the distance of the flight - this can then be added up for the whole year's worth of scheduled flying. 

Emirates is a notable entry into the list, its presence is most likely due to its long average sector lengths and high capacity fleet.

Scheduled Passenger-Kilometres Flown (millions)
Rank Airline Country 2018
1 American Airlines US 330,577
2 Delta Air Lines US 330,034
3 United Airlines US 329,562
4 Emirates UAE 302,298
5 Southwest Airlines US 214,561
6 China Southern Airlines China 200,239
7 Ryanair Ireland 170,900
8 China Eastern Airlines China 166,282
9 Air China China 161,199
10 Lufthansa Germany 158,986

Company Revenue

The last measure comes down to the financials of each carrier. The picture now, of course, looks completely different because of the COVID-19 pandemic, but according to Forbes' World's Largest Public Companies list, Delta Air Lines tops the rankings.

DAL
Hot on its heels, American Airlines trails Delta in terms of revenue and profit. Aviation Image Network/Bailey

Emirates is not a public company because it is government-owned, but it has been slotted into the list to show how it ranks.

Company Revenue 2019
Rank Airline Country Revenue Profit Employees
1 Delta Air Lines US $44.9bn $4.1bn 89,000
2 American Airlines Group US $44.5bn $1.4bn 128,900
3 Lufthansa Germany $42.3bn $2.6bn 135,534
4 United Airlines US $41.9bn $2.3bn 92,000
5 Air France-KLM FR/NL $31.3bn $0.5bn 81,527
6 IAG UK $28.8bn $3.4bn 63,531
7 Emirates UAE $24.2bn $1.24bn 56,575
8 Southwest Airlines US $22bn $2.5bn 58,800
9 China Southern Airlines China $21.7bn $0.5bn 100,831
10 All Nippon Airways Japan $18.6bn $0.9bn 33,719

So there you have it, the world's largest airlines. Topping the majority of the lists, American Airlines could be a potential candidate for the title of "World's largest airline", but despite this, it is not the most profitable because Delta manages to claim that title.