Its subsidiary, Indonesia AirAsia, is the third in the Top 25 list in a Global Flight Pricing report compiled by travel planning website Rome2Rio.
Another unit, AirAsia Philippines, was in the 18th position.
The study showed the average cost per kilometre for flights had increased from 17.75 US cents (70 sen) in 2016 to 18.8 cents (75 sen).
The study also picked Virgin Atlantic as being one of the few airlines that had successfully reduced the cost of its flights. It was 100 in 2016 but had risen in the rankings to 42nd position.
Rome2Rio had analysed over 1.5 million economy-class fares from 200 airlines over a two-month period to calculate the cost per km in US dollars.
Kirsteene Phelan, chief operating officer at Rome2Rio, noted that more airlines were scaling back on their inflight offerings in favour of pay-to-play services to help boost profits.
“We anticipate those seeking to enjoy their journey will look for other options, including rail, to boost their travel experience,” the Telegraph quoted him as saying.
“The AirAsia Group is particularly dominant with three of its airlines in the top 20,” said Phelan.
“Although Qantas (eighth) ranks highly for value, we are often seeing travellers from the UK to Asia and Australia booking with carriers such as Etihad (sixth), Royal Brunei Airlines (19th), China Southern (20th) and Emirates (25th).
“This suggests that while overall value may be high for one airline over another, specific route pricing can vary greatly and travellers need to be vigilant for deals to ensure the best price to their destination.”
The Top 25 best value international airlines are:
- AirAsia X
- India Express
- Indonesia AirAsia
- Primera Air
- IndiGo Airlines
- Etihad
- Ryanair
- Qantas
- WOW air
- Virgin Australia
- Oman Air
- Jet Airways
- Air India Limited
- Sri Lankan Airlines
- Qatar Airways
- Hainan
- Kuwait Airways
- AirAsia Philippines
- Royal Brunei Airlines
- China Southern Airlines
- Lion Mentari Airlines
- Jetstar
- Gulf Air Bahrain
- Cebu Pacific
- Emirates.