Carry-On Size Limits by Airline: American, Delta, United, Southwest
That sounds like a simple rule until you're standing at the gate with a bag that measured fine at home. The gap is almost always the same thing: airlines measure including wheels, handles, and side pockets — the parts a tape measure skips if you're not careful. A bag advertised as "22-inch" by its manufacturer is sometimes 22 inches for the shell alone, which puts the real, wheels-on measurement over the limit before you've packed a single sock.
Key takeaways
- ✓American, Delta, and United cap carry-ons at 22 × 14 × 9 in; Southwest allows a larger 24 × 16 × 10 in.
- ✓Every airline measures including wheels and handles — the detail that gets most bags gate-checked.
- ✓None of the four publish an official weight limit, but you still have to lift the bag into the bin yourself.
- ✓Basic Economy on American can restrict you to a personal item only, with no complimentary carry-on.
- ✓If you fly a mix of airlines, size to the smallest number — 22 × 14 × 9 — not to Southwest's larger allowance.
On this page
Carry-On Size Limits, Airline by Airline
All four dimensions below are the airline's own published limits, not a rounded estimate. Basic Economy fares can restrict you further on some airlines — see the note under the table.
Checked against each airline's own policy — August 2026| Airline | Carry-on max | Personal item max | Weight limit |
|---|---|---|---|
| American Airlines | 22 × 14 × 9 in (56 × 36 × 23 cm) | 18 × 14 × 8 in (45 × 35 × 20 cm) | None specified |
| Delta Air Lines | 22 × 14 × 9 in (56 × 35 × 23 cm) | Fits under the seat — no fixed dimensions published | None (45 total linear in. / 114 cm) |
| United Airlines | 22 × 14 × 9 in (56 × 35 × 23 cm) | 9 × 10 × 17 in (22 × 25 × 43 cm) | None official — must lift it into the bin unassisted |
| Southwest Airlines | 24 × 16 × 10 in (61 × 41 × 25 cm) | Fits under the seat — no fixed dimensions published | No routine weight check |
Why "22 × 14 × 9" Doesn't Always Mean What You Think
The sizer boxes at security and the gate measure the bag exactly as it will travel — wheels, handles, external pockets, and all. A shell that's 22 × 14 × 9 with wheels that add another inch of depth is no longer within the limit. This is the single most common reason a bag that "should" fit gets gate-checked anyway.
It's also why a rigid hardside case and a squishier softside bag aren't equivalent at the same listed dimensions. A softside bag with a bit of give can be gently compressed into a tight sizer; a hardside shell can't. If your bag is right at the limit rather than comfortably under it, softside buys you a small margin that hardside doesn't — worth checking when you browse hardside and softside carry-ons against these numbers.
How to Measure Your Own Bag in Two Minutes
- Retract the handle and stand the bag upright on its wheels, exactly as it will sit going into the sizer.
- Measure length, width, and height including the wheels and handle housing — not just the fabric or hard shell.
- Measure it packed, not empty. A soft-sided bag can round out by half an inch or more once it's full.
- Check the smallest number across the airlines you actually fly. If it's American, Delta, and United, that's 22 × 14 × 9 — Southwest's extra room won't help you on the other three.
Keep this step even for a bag you're buying new: several suppliers list nominal sizes ("20-inch") without publishing the actual boxed dimensions, which is exactly the case for the sets in the "Shop the Fit" section below. A nominal size is a starting point, not a guarantee.
Southwest Gives You More Room — Here's the Real Difference
24 × 16 × 10 inches versus 22 × 14 × 9 works out to roughly 30% more usable volume. That's genuinely useful if Southwest is your primary airline. It's a liability if you fly a mix of carriers and buy a bag sized to Southwest's limit — it will get gate-checked the moment you fly American, Delta, or United.
The practical rule: unless you fly almost exclusively on Southwest, size your bag to 22 × 14 × 9 so it works everywhere, and treat any extra room on Southwest as a bonus rather than a baseline.
What Happens If Your Bag Doesn't Fit
Oversized bags get gate-checked, not refused outright — you'll still get the bag back at your destination (or at the jet bridge on many domestic flights), but you lose in-cabin access to it and may pay a fee depending on your fare type. Your personal item stays with you regardless, which is one more reason it's worth choosing one deliberately rather than as an afterthought.
Shop the Fit
Look for a carry-on advertised at 21–21.5 inches rather than a full 22 — that gives you room for wheels and handles before you hit the limit. Three from our own catalog, with the same honesty this article asks of you: none of these suppliers publish exact per-case exterior dimensions, so measure the piece you receive against the numbers above before your first flight.
Browse the full range in Luggage & Travel or Handbags if none of the three above are quite right.
Frequently Asked Questions
Tap a question to expand it.
Do all airlines measure carry-ons the same way?
The four major U.S. carriers are close but not identical. American, Delta, and United all use 22 × 14 × 9 inches; Southwest allows a larger 24 × 16 × 10. All of them measure including wheels and handles, not just the bag's shell.
Does the carry-on limit include wheels and handles?
Yes, for all four airlines. This is the detail that catches most travelers — a bag that's exactly 22 × 14 × 9 without wheels is already over the limit once they're attached.
Is there a weight limit for carry-on bags?
None of the four airlines publish an official carry-on weight limit for domestic flights. United and others still expect you to lift your own bag into the overhead bin without help from crew, which functions as a practical limit even without an official number.
What if I have a Basic Economy ticket?
Check your fare rules before you pack. American Airlines' Basic Economy fare can limit you to a personal item only on certain routes, with no complimentary full carry-on — that's a fare restriction, not a bag-size issue.
Can a slightly oversized bag still get through if it's soft-sided?
Sometimes, since a softside bag with give can be gently compressed into a rigid sizer box in a way a hardside shell can't. It isn't guaranteed, and gate agents can enforce the limit strictly on a full flight — treat it as a small margin, not a workaround.
How often do these limits change?
Rarely, but airlines do adjust policy without much notice. This page is checked every six months and the date at the top reflects the last verification — always confirm against the airline's own page linked above before a trip that matters.
None of these numbers are complicated on their own — the trouble is always the wheels, the handle, and the fare rule nobody reads until they're at the gate. Measure the bag as it will actually travel, size to the tightest airline on your itinerary, and the rest takes care of itself. Buying a carry-on as a gift instead? Our gift shop has travel-ready picks for the frequent flyer on your list.
Sources: American Airlines · Delta Air Lines · United Airlines · Southwest Airlines