Carry-On Rules for US Airlines: The Full Guide (2026)
American, Delta, United, Southwest, Alaska, JetBlue, Spirit, Frontier, Allegiant, Sun Country—carry-on size, weight, and what's free vs paid.
The US airline industry has one of the most confusing carry-on landscapes in the world. Most major carriers use a near-identical size limit — but the difference between what is free and what costs extra depends entirely on your fare class and airline. This guide covers 10 US airlines, from full-service majors to ultra-low-cost carriers (ULCCs).
The US Standard: Size vs. Weight
Unlike most international carriers, US airlines do not publish weight limits for carry-on bags (with very rare exceptions). The practical limit is your ability to lift the bag overhead. This is a meaningful difference from European carriers — you can bring a 15 kg carry-on on American Airlines without a policy violation (you just have to lift it yourself).
The near-universal US size limit is 22×14×9 inches (56×35.5×23 cm) including wheels and handles. Southwest is more generous at 24×16×10 inches.
Full-Service Major Airlines
American Airlines
| Fare | Carry-on (overhead) | Personal item | Fee if not included |
|---|---|---|---|
| Basic Economy | Not included | 1 under-seat item free | $25–$75+ at airport |
| Main Cabin (Economy) | 1 × 22×14×9 in included | 1 under-seat item free | — |
| Business/First | 1 × 22×14×9 in included | 1 under-seat item free | — |
Size: 22×14×9 in (56×35.5×23 cm), no weight limit Basic Economy trap: Basic Economy fares (marked "BE") do not include overhead bin access. Your options: pay to upgrade to Main Cabin, add the carry-on as an ancillary, or pack into a personal item only. AAdvantage status: Gold, Platinum, Platinum Pro, and Executive Platinum get overhead bag on Basic Economy (benefit varies by tier).
Delta Air Lines
| Fare | Carry-on (overhead) | Personal item | Notes |
|---|---|---|---|
| Basic Economy | Not included | 1 under-seat item | Overhead at gate = fee |
| Main Cabin / Comfort+ | 1 included | 1 under-seat item | — |
| First / Business | 1 included | 1 under-seat item | — |
Size: 22×14×9 in (56×35.5×23 cm), no weight limit Basic Economy note: Delta's Basic Economy is labeled in the booking flow. SkyMiles Medallion status (Silver and above) waives the carry-on restriction on Basic Economy tickets on domestic flights. Carry-on enforcement: Delta is moderate in enforcement. Gate agents typically give benefit of the doubt on borderline bags.
United Airlines
| Fare | Carry-on (overhead) | Personal item | Notes |
|---|---|---|---|
| Basic Economy | Not included | 1 under-seat item | In-cabin bag = fee |
| Economy (standard) | 1 included | 1 under-seat item | — |
| Business / Polaris | 2 included | 1 under-seat item | — |
Size: 22×14×9 in (56×35.5×23 cm), no weight limit Basic Economy ("N" fare): Carry-on not included. MileagePlus Premier members retain carry-on benefit regardless of fare. Tip: United is strict about enforcing Basic Economy at the gate on some routes — more so than Delta or American in recent reports.
The Outlier: Southwest Airlines
Southwest has the most passenger-friendly carry-on policy of any US airline:
| Fare | Carry-on (overhead) | Personal item | Checked bags |
|---|---|---|---|
| All fares | 1 × 24×16×10 in — FREE | 1 — FREE | 2 × free |
Size: 24×16×10 in (61×40.6×25.4 cm) — more generous than all other US majors No Basic Economy: Southwest does not sell stripped basic fares with reduced bag access. Every passenger on every fare gets the same carry-on rights. No change fees and free checked bags make Southwest the best value for bag-heavy travelers despite sometimes-higher base fares.
Alaska Airlines
| Fare | Carry-on (overhead) | Personal item | Notes |
|---|---|---|---|
| Saver (basic economy) | Not included | 1 under-seat item | Overhead = $65 at gate |
| Main Cabin / First | 1 included | 1 under-seat item | — |
Size: 22×14×9 in (56×35.5×23 cm), no weight limit Saver fares: Strictly boards last. Overhead bin access is not included. MVP and MVP Gold status waives restriction. Alaska's carry-on is included on all non-Saver fares — more generous than American/Delta/United Basic Economy on comparable price tiers.
JetBlue Airways
| Fare | Carry-on (overhead) | Personal item | Notes |
|---|---|---|---|
| Blue Basic | Not included | 1 under-seat item | — |
| Blue / Blue Extra / Mint | 1 included | 1 under-seat item | — |
Size: 22×14×9 in (56×35.5×23 cm), no weight limit Blue Basic = stripped fare with no overhead bin. JetBlue enforces this more consistently than some competitors. Mint (Business): 2 carry-on items permitted. TrueBlue Mosaic status waives Blue Basic carry-on restrictions.
Ultra-Low-Cost Carriers (ULCCs)
Spirit Airlines
| Fare | Carry-on (overhead) | Personal item | Carry-on fee |
|---|---|---|---|
| All fares | Not included on any fare | 1 × 45×35×20 cm — FREE | $35–$100+ (online to gate) |
Spirit includes nothing in the overhead on any fare. The personal item (18×14×8 in / 45×35×20 cm) under the seat is the only free item. Overhead carry-on is purchased separately. Gate prices are significantly higher than online prices. No weight limit published for the carry-on or personal item. Spirit Saver$ Club membership reduces bag fees moderately.
Frontier Airlines
| Fare | Carry-on (overhead) | Personal item | Carry-on fee |
|---|---|---|---|
| Economy (no bundle) | Not included | 1 under seat — FREE | $39–$99 (online vs. gate) |
| Classic Plus / Premium | Included | 1 under seat | Included |
Size: 24×16×9 in (61×40.6×23 cm) for carry-on; 14×18×8 in for personal item Same model as Spirit for base fares — nothing in the overhead without paying extra. Elite status (100K, 50K) includes carry-on fee waivers.
Allegiant Air
| Fare | Carry-on (overhead) | Personal item | Notes |
|---|---|---|---|
| Base fare | Not included | 1 under seat (no published limit) | — |
| Total Package bundle | Carry-on + checked bag + seat | Included in bundle | Often best value |
Size: 22×16×9 in (56×40.6×23 cm), weight up to 40 lb (18 kg) Allegiant's unusual 40 lb (18 kg) weight limit is the most generous published cabin bag weight limit among US carriers. Total Package: Bundles carry-on + checked + seat selection at a flat price — can be competitive vs. a-la-carte.
Sun Country Airlines
| Fare | Carry-on (overhead) | Personal item | Notes |
|---|---|---|---|
| Basic / Economy | Not included (by default) | 1 small item — FREE | Add cabin bag from ~$25 |
| Bundle fares | May include carry-on | 1 under seat | Check at booking |
Size: 24×16×11 in (61×40.6×28 cm) — among the larger US ULCC limits Sun Country is a hybrid ULCC with leisure focus from Minneapolis (MSP). Carry-on add-on pricing is competitive with Spirit/Frontier.
Full Comparison Table (2026)
| Airline | Size (in) | Weight limit | Free on base fare? | Basic Economy trap? |
|---|---|---|---|---|
| American | 22×14×9 | None | No (Basic Economy) | Yes |
| Delta | 22×14×9 | None | No (Basic Economy) | Yes |
| United | 22×14×9 | None | No (Basic Economy) | Yes |
| Southwest | 24×16×10 | None | YES — all fares | No Basic Economy |
| Alaska | 22×14×9 | None | No (Saver fares) | Yes |
| JetBlue | 22×14×9 | None | No (Blue Basic) | Yes |
| Spirit | 22×18×10 | None | Never free | N/A |
| Frontier | 24×16×9 | None | Never free (base) | N/A |
| Allegiant | 22×16×9 | 40 lb (18 kg) | Never free (base) | N/A |
| Sun Country | 24×16×11 | None | Not by default | N/A |
Key Takeaways
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Southwest is the best for carry-on travelers in the US — no restrictions, larger size, and includes two free checked bags.
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Basic Economy on AA/Delta/United is a trap — the base fare looks cheap but the carry-on exclusion often makes the total cost similar to or higher than standard economy with carry-on included.
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Spirit and Frontier never include overhead bin access — always add a carry-on at booking (never at the gate, where prices can be 2–3x higher).
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US airlines do not weigh carry-ons — this is a significant advantage over European carriers. A 12–15 kg carry-on is common and legal on US domestic flights.
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Status matters — frequent flyer status on American, Delta, and United waives Basic Economy carry-on restrictions, which is one of the most valuable low-tier status benefits.
Frequently asked questions
Do US airlines have a weight limit for carry-on bags?▾
Most US airlines (American, Delta, United, Southwest, Alaska, JetBlue) do not publish a weight limit for carry-on bags. The standard is that you must be able to lift it into the overhead bin safely. Spirit, Frontier, and Allegiant also have no published weight limits. Only a few US carriers apply actual weight checks.
Does basic economy on US airlines include a carry-on bag?▾
It depends on the airline. Southwest includes a full carry-on on every fare. Alaska, JetBlue, Delta, United, and American all have basic economy fare tiers that restrict overhead bin access to mid-tier and higher fares. Spirit and Frontier do not include overhead bin access on any fare — only an under-seat personal item is free.
What is the standard carry-on size for US airlines?▾
The industry standard in the US is 22×14×9 inches (56×35.5×23 cm), including wheels and handles. American, Delta, United, Alaska, and JetBlue all use this or a very similar limit. Southwest uses 24×16×10 inches (61×40.6×25.4 cm), which is more generous.
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