Five US Airlines: Frontier Airlines, Hawaiian Airlines, JetBlue Airways, Allegiant Air, and Alaska Airlines currently offer some of the cheapest economy class seats in the United States. Using RASM as a baseline metric, otherwise known as revenue per available seat mile, Frontier claims the top spot as the airline delivering the most value. With legacy airlines like 
United Airlines, 
Delta Air Lines, and 
American Airlines having RASMs of between $0.167 and $0.178, these five airlines are up to 75% cheaper than the mainline carriers.
Interestingly, however, the top five is not fully composed of low-cost carriers; rather, a combination of full-service carriers, budget airlines, and those somewhere in between comprises the United States’ cheapest airlines. From bare-bones low-cost flying to full-service carriers offering exceptional value, these are five of the cheapest economy seats available in the United States.
Alaska Airlines
$0.146 per seat-mile
While 
Alaska Airlines may not immediately come to mind as a low-cost airline, the carrier consistently provides some of the best value in the US aviation industry. Despite operating as a full-service airline, Alaska maintains a relatively low RASM of $0.146 per seat mile, making it one of the cheapest traditional carriers in the country. The airline combines competitive fares with noticeably higher-quality onboard service than most ultra-low-cost competitors.
For passengers looking to fly Alaska, the carrier operates an extensive route network across the West Coast of the US. This includes service predominantly in Alaska, Washington, California, Oregon, and the major cities. The airline also operates an ever-growing network to the East Coast as well as to Hawaii, bolstered by the carrier’s 2024 merger with Hawaiian Airlines. In April, Alaska launched its first-ever European flight from Seattle to Rome, complementing its 2025 Asian international services.
Onboard, passengers flying in economy benefit from complimentary snacks, free Starlink WiFi on all 344 aircraft by 2027, and strong customer service. The airline’s Mileage Plan loyalty program is also regarded as one of the strongest in the US, especially for economy passengers, as it awards miles based on distance traveled rather than amount paid. With Alaska’s strong offerings across multiple fronts, the carrier continues to represent a strong economy class option within the US and abroad today.
Allegiant Air
$0.1313 per seat-mile
Coming in at number four, Allegiant Air is the first true ultra-low-cost carrier on this list. With a unique niche in the US airline industry, focusing almost exclusively on underserved leisure routes, Allegiant is able to take advantage of unique cost savings to offer cheap fares to its passengers. The airline frequently advertises one-way fares under $50, with promotional sales occasionally dropping below $30. Unlike traditional airlines that focus on large hub airports, Allegiant instead connects smaller regional airports directly to vacation destinations such as Las Vegas, Orlando, Phoenix, and Florida.
Allegiant’s low-cost model allows it to offer a RASM of $0.1313, just barely higher than the third-cheapest airline. Much like all low-cost carriers, Allegiant relies heavily on revenue generated from additional fees, like baggage fees, seat selection, and onboard purchases, but still delivers significant value despite these fees. However, aside from cost, another advantage that Allegiant offers over other carriers is convenience. Allegiant often flies from smaller airports with a more relaxed airport experience, which can make budget travel less stressful overall.
With Spirit’s collapse, Allegiant is now the second-largest ultra-low-cost carrier in the United States, second only to the top airline on this list. While passengers should expect minimal onboard amenities and strict baggage policies, those willing to travel light can often save substantial amounts of money. For budget-conscious leisure travelers, especially those living near airports served by Allegiant, the carrier remains one of the strongest low-cost options in the American market.
JetBlue Airways
$0.131 per seat-mile
JetBlue has long occupied somewhat of a middle ground between ultra-low-cost carriers and traditional legacy airlines. Currently with 293 aircraft in its fleet, JetBlue is significantly larger than both of the top two airlines on this list. The New York-based carrier offers a robust route network across the East Coast of the United States, the Caribbean, Latin America, and more recently, parts of Europe. The airline’s expansion into transatlantic operations has added more competition to markets that were traditionally dominated by legacy carriers, bringing the airline’s lower ticket costs to a larger audience.
In terms of numbers, JetBlue has a RASM of $0.131, putting it at a solid number three. This is bolstered by the carrier’s significant legroom in economy. At 32.3 inches, this means JetBlue offers the most generous legroom of any US carrier’s economy offering, and more than the vast majority of international carriers as well. Additionally, JetBlue was one of the first airlines in the world to offer complimentary high-speed WiFi on its aircraft, starting a trend that now encompasses most of the industry. Even with these extras, JetBlue maintains its competitive pricing on most routes, even though the airline is currently struggling with its profitability.
While not directly related to economy class, JetBlue also offers one of the cheapest premium products in the United States. The carrier’s “Mint” business class seats and suites frequently receive awards as among the best business class products offered by a US airline. On transatlantic flights, JetBlue Mint can be thousands of dollars cheaper than competitors’ offerings while including all the same benefits, now also featuring JetBlue Blue House lounge access. For travelers who value comfort without spending significantly more, JetBlue remains one of the best options in the country.
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Hawaiian Airlines
$0.12 per seat-mile
Rather surprisingly, Hawaiian Airlines takes second place for the cheapest US economy seats. Considered a full-service airline and connecting the world to the Hawaiian Islands, Hawaiian Airlines’ RASM is much lower than every other full-service US Airline and cheaper than many low-cost carriers. At just $0.12 per seat-mile, Hawaiian provides an exceptional balance between long-haul flying and low-cost options.
Passengers in Hawaiian’s economy class enjoy many of the same benefits as when flying a major US carrier. This includes free carry-on luggage, complimentary meals on longer flights, and free inflight entertainment. Hawaiian also has plans to introduce Starlink WiFi to its entire fleet, with installation on its Airbus A330 fleet expected to begin soon. On the loyalty rewards side, like Alaska, Hawaiian awards frequent flyer miles based on distance flown rather than the price of a ticket, allowing passengers traveling long-haul in Hawaiian economy class to benefit from low prices and earn significant mileage as well.
In terms of pricing, Hawaiian frequently offers flights from the US West Coast to Hawaii for less than $100 one-way. For flights from Hawaii to destinations like New York, tickets can be found for about $500 round-trip, but increase during peak travel season. Another reason Hawaiian manages to keep costs relatively low is its highly focused route network, concentrating almost exclusively on flights to Hawaii, including those between the individual Hawaiian islands. Thus, Hawaiian’s combination of affordability and full-service amenities makes it one of the strongest value propositions among US airlines.
Frontier Airlines
$0.095 per seat-mile
With Spirit Airlines having shut down operations, Frontier Airlines is now the largest and cheapest low-cost carrier in the United States. With a fleet of 162 Airbus A320 family aircraft at just 4.6 years old on average, Frontier’s business strategy revolves around simplicity and efficiency. With an all-Airbus fleet, each with between 180 and a whopping 240 seats on its Airbus A321neo aircraft, Frontier is able to maximize seat density while reducing maintenance and training costs. This in turn allows the carrier to provide lower fares to passengers, with service to over 120 destinations from its bases across the country, including Atlanta, Denver, and Orlando.
Looking at cost, Frontier is well known for offering cheap fares across its route network, with flights typically starting as low as $39 one way. In terms of RASM, Frontier comes in at $0.095 per seat mile, more than two cents cheaper than the next airline on this list. Frontier’s low cost per seat mile reflects the carrier’s identity as an ultra-low-cost carrier, with base fares starting at extremely low prices while add-ons for things like seat selection, carry-on bags, checked bags, and priority boarding all incur at an additional cost. Additionally, unlike on mainline carriers, passengers on Frontier do not receive any amenities like complimentary snacks, beverages, or inflight entertainment.
Uniquely, Frontier is also one of the few airlines in the world that offer unlimited flying passes. Known as the “GoWild!” Pass, Frontier customers can purchase subscription-style flight access for a fixed price, currently just $199 for the summer, and fly as often as they want. These flights can be booked within 24 hours of departure for domestic flights, with passengers only required to pay the applicable government-imposed taxes and fees, usually just $5.60 for flights within the US. While the GoWild! Pass requires flexibility and comes with additional restrictions; it has become popular with passengers looking to save even more.
