Here are the 10 cheapest airlines (hidden fees included!) in the U.S.

Black Friday is coming up and American consumers have their deal-dars on high alert, searching for bargains on clothing, electronics and, of course, flights. Google searches for airfare deals skyrocket as travelers hope for an affordable winter escape, so knowing which airlines usually offer the cheapest routes is certainly a great place to start.

To separate the true budget heroes from the super-low fares that are anything but after all the fees, passenger rights expert AirAdvisor published its first-ever ranking of the 10 most affordable U.S. airlines for 2025. The ranking is based on a metric called RASK: revenue per available seat kilometer. It’s the number airlines use to measure how much they actually earn per seat, per kilometer flown, including baggage, seat selection and "convenience" fees.

"RASK is the only metric that reveals the real cost for passengers," said Anton Radchenko, CEO of AirAdvisor, in an official statement. "It cuts through the illusion of 'low-cost.'"

According to this analysis, the cheapest U.S. airline is Frontier Airlines, at $0.095 per seat mile. The ultra-low-cost carrier is more than a penny per mile cheaper than its nearest rival. If you’re flying within the U.S., Central America or Mexico and can survive without legroom or complimentary anything, Frontier is the cheapest way to go by far.

At number two is Spirit Airlines, at $0.11 per seat mile. Spirit stays true to its "bare fare" philosophy: the ticket only gets you a seat and one personal item. Everything else costs extra, but at least that transparency makes it easier to keep your total spend under control. As long as you can pack light, you can’t beat the value of Spirit.

Hawaiian Airlines comes in at number three, at $0.12 per seat mile. Hawaii’s flagship carrier surprisingly outranks several low-cost airlines on price and reliability. If you're looking for a tropical escape, this combo of affordability and dependability is a real winner.

Rounding out the top 10 are JetBlue, Allegiant, Alaska and Southwest. 

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Ten cheapest U.S. airlines according to RASK analysis:

1. Frontier Airlines ($0.095 per seat mile)
2. Spirit ($0.11)
3. Hawaiian Airlines ($0.12)
4. JetBlue ($0.131)
5. Allegiant Air ($0.131)
6. Alaska Airlines ($0.146)
7. Southwest Airlines ($0.157)
8. United Airlines ($0.167)
9. American Airlines ($0.172)
10. Delta Airlines ($0.178)