Airlines - passenger kilometers flown

The three largest U.S. full-cost carriers sit atop the list of passenger kilometers (RPKs) flown worldwide in 2020 with American Airlines managing to reach top spot with 124 billion RPKs. On the third place was Delta with 106.5 billion, followed by United Airlines with 100.2 billion RPKs.

Revenue passenger kilometers

Revenue passenger kilometers (or revenue passenger miles, in some territories) are a measure of passenger demand in a given market. They are calculated by multiplying the number of revenue-paying passengers aboard an aircraft by the distance the aircraft traveled. Often RPKs are compared to available seat kilometers (ASKs), which are the number of seats available for sale on an aircraft multiplied by the distance flown. ASKs effectively measure supply in a given market, with the goal of airlines being to match their ASKs offered with their RPKs flown.

Airline metrics

Across most airline industry metrics the large full-cost U.S. airlines dominate. Looking at only the number of passengers flown, American and Delta again sit in first and second place, with U.S. low-cost carrier Southwest coming in third just ahead of United. Revenue figures tells a similar story, but with German national carrier Lufthansa replacing Southwest. However, when considering the number of airport pairs served, all the U.S. carriers are beaten out by Irish low-cost carrier Ryanair, who serve nearly 50 percent more airport pairs than American Airlines.