Cheapest Airlines in the US: Budget Carrier Rankings 2023

Written By Amy Lancelotte

9 minutes read

Flights can be one of the more expensive components of any trip, so it’s useful to know the cheapest airlines in the US if you need to save money. It’s not surprising that most of the budget carriers we reviewed rank higher on our list, meaning they have lower total passenger revenue per seat mile.

• The US airlines we reviewed made over $900 million in passenger revenue in 2022.
• These 10 airlines had over 1 trillion available seat miles.
• The total revenue for airlines per seat mile ranges from $0.1048 to $0.1729.

Let’s get to our AirAdvisor list of the cheapest airlines to fly that are based in the US and explore the outliers. Some airlines billed as low-cost don’t rank as well as you might think.

Top 3 Cheapest Airlines in the US

#1 Frontier Airlines

What is the cheapest airline in the US? Based on our research, Frontier Airlines has the lowest total passenger revenue per seat mile of the 10 airlines we reviewed. Their number of $0.1048 per seat mile seems low, in fact, they all do, but think about how many actual miles your plane is flying. Costs can definitely start to mount up.

Frontier Airlines is often referred to as an ultra-low-cost carrier, and this certainly rings true based on our research. US airlines don’t get any cheaper than this as a whole. For destinations in the US, Central America, and Mexico, check with them first - they are more than $0.01 per mile cheaper than the next airline.

#2 Spirit Airlines

The second-cheapest airline on our list is Spirit Airlines, another ultra-low-cost carrier that flies throughout the US, the Caribbean, and Latin America. As for their total revenue per available seat mile - that’s $0.1167, which, as mentioned, is more than one cent above our number 1 cheapest airline.

Spirit Airlines is known for promoting the “Bare Fare,” which is simply a charge for your seat and one personal item. There are no frills with Spirit, but that means it’s much easier to keep your overall flight cost low.

#3 Allegiant Air

Rounding out our top 3 cheapest airlines is Allegiant Air, which, unsurprisingly, is another ultra-low-cost airline. Allegiant’s revenue per seat mile is a whole $0.02 more than Frontier’s and was $0.1250 in 2022.

Allegiant Air is still a good option for budget-conscious travelers and is still one of the cheapest domestic airlines, but this airline only flies within the US. Zero international destinations are available currently, and the best they can do is get you near (not to) Canada.

How the Others Stack Up - Spots 4 Through 10

#4 Hawaiian Airlines

Once we get to the number 4 spot, we start to see some anomalies. Hawaiian Airlines is not considered a low-cost carrier in the technical sense, although their AirAdvisor Cheapest Airline Score might beg to differ. As the highest-ranking non-budget airline, Hawaiian Airlines’ seat mile revenue in 2022 was $0.1253 - just a shade above Allegiant’s.

Hawaiian Airlines is an ideal choice for travel to and from Hawaii and its major islands from Asia, the South Pacific, and of course, North America. If you’re planning a trip that involves the Aloha State in any way, Hawaiian Airlines is often a cheap option.

Plus, based on our overall research, Hawaiian Airlines is by far the best combination of reliability and price of any airline we reviewed. You can also dive into the Most Reliable Airlines in the US if reliability is a crucial factor for you.

If you’ve experienced an unreliable airline and your flight has been delayed by 3 hours or more, compensation may be an option. Use our free flight checker to see if you qualify.Check Your Flight

#5 JetBlue

The fact that jetBlue is a low-cost airline (not ultra) means its position after the top 3 makes sense. It’s just a little surprising that Hawaiian Airlines ranks above this so-called budget-friendly carrier.

In 2022, jetBlue’s total revenue per seat mile was $0.1332, which is more than $0.02 lower than the number 6 airline. It’s safe to say that after jetBlue, we are leaving the true budget airlines behind.

#6 Alaska Airlines

After Hawaiian Airlines, Alaska Airlines is the next cheapest non-budget airline in the US. The carrier offers domestic flights and flights from US cities to Canada, Mexico, Costa Rica, Guatemala, The Bahamas, and Belize. Their revenue per seat mile is $0.1587, which puts them above the overall $0.1442 average of our 10 airlines.

Although Alaska Airlines is above the mid-range of our cheapest airlines, don’t immediately rule them out. The company offers flash sales throughout the year, so it’s worth checking their prices, especially if you want to avoid a no-frills budget airline.

#7 United Airlines

At $0.1615 per seat mile, United Airlines is certainly not the cheapest airline out there, but it is the top major US airline to appear in the rankings. Although fares may be higher than average with United, the airline offers extensive routes throughout the world, more specifically to the 6 inhabited continents.

If you’re planning to fly long distances, United is a solid option that will balance price and comfort.

#8 American Airlines

Almost another cent higher per seat mile than United, American Airlines, at number 8, is definitely one of the pricier carriers you can choose. Their 2022 revenue per seat mile was $0.1713 and is not far off the last two entries on our list.

American Airlines is another of the US’ major carriers with an enviable selection of routes. If you need to get somewhere on a certain day at a certain time, check out the fares with American, as the flights are frequent, and over 350 destinations in 60 countries are available.

#9 Delta Airlines

Delta Airlines is not the most expensive of our 10 airlines, but it’s close. They take the number 9 spot with a revenue per seat mile of $0.1724. As an airline, Delta has many strengths, but price isn’t usually one of them.

Delta offers flights all over the world, so there is a place for them on the itinerary of even the most budget-conscious traveler. Their website has a section for current flight deals, and you can subscribe to their newsletter to be informed whenever new sales are starting.

Delta is among the most reliable airlines we reviewed, which might help explain their higher prices. If you are one of the unlucky ones and experience an interruption on a Delta flight (or a flight from any other airline), we can help. It’s often possible to claim compensation for delayed flights and instances of denied boarding.

#10 Southwest Airlines

Although Southwest Airlines is technically the world’s largest low-cost carrier, the airline’s total revenue per seat mile is the highest on our list at $0.1729. This isn’t much more than Delta, but travelers who think that Southwest offers the lowest prices are in for a surprise. This brings forth the question of whether Southwest should even be considered a budget carrier.

That being said, at least part of the reason for Southwest’s higher prices is that they don’t just offer customers the basic seat and one personal item. There are additional fare categories that include things like seat selection, checked bags, and upgraded seats, which will inevitably drive up the revenue per seat mile.

According to our extensive research, budget airlines aren’t always the most reliable. If you’ve flown with any of the airlines on our list and encountered a delay, you might be eligible for compensation.Check now!

Cheapest International Airline in the US

Determining the cheapest international airline is easy if you take “international” in the truest sense of the word. Of the airlines that fly to any country other than the US, the cheapest airline would be the same as our overall winner - Frontier Airlines. They fly to the Caribbean, Mexico, and Central America. But, in truth, their destinations are quite limited.

For anyone searching for the cheapest international airline that flies to destinations like Asia, Europe, South America, and Africa, the frontrunner is United Airlines. Some other airlines fly to one or two of these destinations, but United Airlines is the cheapest carrier that has multiple flights throughout North America and 5 other continents.

AirAdvisor US Airline Affordability Rating - Top Carriers Ranked

Our Data

To determine the cheapest airlines in the US, our methodology was fairly simple. We looked at each airline’s publicly available balance sheet for 2022. We used the total passenger revenue per seat mile that they published to rank them. The lower the dollar amount, the higher the ranking.

Conclusion

Many things go into determining the ideal airline for your next business trip or vacation. If you’d like an overall view of these same 10 airlines and how they rate in 9 different categories, including cost, check out our post on the Top 10 Airlines in the US.

Our AirAdvisor Cheapest Airlines Score should be used any time you are planning to book a flight. When cost is important to you, check with the highest-ranked airline that flies to your destination first and then expand out from there. Many factors can influence the cost of an individual flight, like when you book and when you fly, and airlines also offer sales and discounts when flights aren’t as full as they want. Keep this in mind, and use our rankings as a guide to start your search.

FAQ

What are the cheapest airlines in the US?

Based on our AirAdvisor Score, Frontier Airlines is the cheapest airline in the USA. They have the lowest total passenger revenue per seat mile of the 10 airlines we included in our research. After Frontier Airlines, Spirit Airlines and Allegiant Air complete the top 3 cheapest options for US-based air travel using this same metric.

What is the cheapest international airline in the US?

Most of the US airlines we reviewed fly internationally to places like Mexico, the Caribbean, and Canada, but the cheapest international airline that flies to Oceania, Africa, Asia, Europe, and South America as well is United Airlines.

Are budget airlines always the cheapest airlines?

No, not always. According to the data we gathered on passenger revenue per seat mile, jetBlue, a popular low-cost airline, is more expensive overall than Hawaiian Airlines. Additionally, Southwest Airlines, the largest budget carrier in the world, had the highest passenger revenue per seat mile on our list, earning it last place (the most expensive).