The largest airline in the world can be measured in several ways. As of 2024, United Airlines was the largest in terms of available seat miles (ASM),[1] revenue seat miles (RPM),[2] mainline fleet size,[3] the number of both mainline employees[4] and destinations served;[5] Delta Air Lines was the most valuable by revenue, assets, market capitalization, and brand value;[6] American Airlines Group carries the most passengers and has the most employees when American Eagle is included; FedEx Express
Financials
Revenue
Note that Emirates is a state-owned company, and is thus not included in this list of public companies. Its 2024 revenue was estimated to be around $37.4B. Qatar Airways Group is similarly privately held with its 2024 revenue of around $22.2B (with Emirates included).
Earnings
Market capitalization (April 2026)
Brand value
Capacity
Airlines by available seat miles (ASMs)
Numbers are listed in billions of available seat miles.
Airline groups by available seat kilometers (ASKs)
Numbers are listed in billions of ASKs.