The analysis compared 23 European airlines using RASK (revenue per available seat kilometre), an indicator designed to measure how much revenue airlines generate from each seat flown.

This measure takes into account additional revenue sources, including checked baggage and seat selection, rather than advertised fares alone.

Carrier distinctions

Wizz Air topped the list of the cheapest airlines, with a RASK of €4.33 per passenger-kilometre, while Ryanair followed at €5.56, with TAP also among the three least expensive carriers included in the study.

TAP recorded a RASK of €6.96 in 2025, down from €7.13 the previous year, as the 0.17 cent reduction placed the Portuguese flag carrier 17th in AirAdvisor’s ranking of the most expensive airlines.

At the other end of the scale, Widerøe recorded 32 cents per seat-kilometre, substantially higher than any other carrier examined, largely attributed to its distinctive operating model: a fleet of around 70 turboprop aircraft serving short, low-density domestic routes across Norway.

Airline market

Anton Radchenko, CEO of AirAdvisor, said Widerøe should effectively be considered separately from the traditional European airline market because it often provides the only scheduled connection for remote communities.

Excluding Widerøe, British Airways had the highest RASK, at 8.88 cents per passenger-kilometre, followed by Air France at 8.50 cents and Lufthansa at 8.45 cents.

British Airways was also the only airline among the most expensive carriers to record a notable increase between 2024 and 2025, with its RASK rising by 0.38 cents from 8.50 to 8.88 cents, while Air France increased by 0.07 cents and Lufthansa fell by 0.10 cents.

Revenue models

The study found that nine of the 14 major European airlines assessed reduced their revenue per available seat kilometre last year.

Ryanair registered the sharpest decline, with its figure falling by 2.87 cents, from 8.43 to 5.56 cents, which represents a reduction of around 34 percent in a single year.

Finnair also recorded a substantial fall, dropping from 7.97 to 6.22 cents, while Iberia declined from 8.24 to 7.08 cents.

Radchenko added that the figures point to an increasingly pronounced difference between the revenue models of traditional full-service airlines and high-volume carriers.

Journey cost

For passengers, he argued, the choice of airline on routes where several carriers compete can now have a significant impact on the overall cost of a journey.

According to the AirAdvisor chief executive, the gap between the most and least expensive categories is increasingly measured in several cents per kilometre rather than fractions of a cent.

AirAdvisor said the 4.55-cent difference between the highest and lowest RASK in the study would amount to roughly €52 per seat on a 1,157-kilometre journey.

The five airlines that increased their RASK in 2025 all did so by less than 0.38 cents, with British Airways recording the largest increase.