Carry-on size is the airport rule most likely to cost you money at the last minute. Guess it wrong and your bag gets pulled aside at the gate, checked into the hold, and sometimes charged a fee — all while everyone else boards. The frustrating part is that there is no single global number: the limit depends on the airline you fly.
This guide covers the standard carry-on dimensions, why they vary, who actually sets them, and how to make sure your bag makes it into the cabin.
Table of Content
- Quick answer
- The standard carry-on size
- Who sets the limit (it is not the TSA)
- Is there a weight limit?
- Carry-on vs personal item
- International and budget airlines
- What if your bag is too big
- How to measure your bag
- FAQs
Quick answer
For most major US airlines, the maximum carry-on size is 22 x 14 x 9 inches (56 x 36 x 23 cm), including wheels and handles. The airline sets this limit, not the TSA, so it varies — budget and international carriers are often smaller. Most US airlines have no carry-on weight limit; many international ones do. You are also usually allowed one smaller personal item that fits under the seat.
The standard carry-on size
The most common carry-on limit, used by major US airlines including Delta, United, American and Alaska, is 22 x 14 x 9 inches (56 x 36 x 23 cm). If you buy a suitcase marketed as “carry-on” or “cabin” size, it is usually built to fit this standard.
One catch: airlines measure the bag at its largest points, wheels and handles included. A case that measures 22 inches in the body can measure 23 or 24 inches once you count the wheels, which is enough to get it flagged. When you shop, check the overall dimensions, not just the packing depth.
Who sets the limit (it is not the TSA)
A common mix-up: people assume the TSA sets carry-on size. It does not. The TSA runs security screening and the liquid rules, but the size of your cabin bag is set by each airline. That is why the same suitcase can be fine on one carrier and too big on another, and why there is no single “legal” carry-on size.
Is there a weight limit?
It depends where you fly. Most major US airlines set only a size limit for carry-ons, not a weight limit. Many international and budget airlines do enforce a carry-on weight limit, commonly in the range of 7 to 10 kg, and they will weigh your bag at the gate. If you are flying outside the US, check the weight allowance as well as the dimensions.
Carry-on vs personal item
Most fares include two pieces: your carry-on and a smaller personal item that fits under the seat in front, such as a handbag, laptop bag or small backpack. The personal item has its own, smaller size limit that also varies by airline. See our guide to airline personal item size limits for the details.
International and budget airlines
The 22 x 14 x 9 inch standard is a US norm, not a global one. Many European, Asian and budget airlines allow a smaller cabin bag, and low-cost carriers often split the allowance into a small free bag that fits under the seat and a larger cabin bag you pay for. Before an international or budget flight, always confirm the exact cabin bag dimensions on the airline’s own site.
What if your bag is too big
If your bag is over the limit, or the overhead bins fill up, it gets gate-checked into the hold. That can come with a fee, and you wait for it at baggage claim on arrival. Gate agents sometimes use a sizer box to spot-check bags, particularly on busy flights. If you think a checked bag is likely, it is usually cheaper to book it in advance — our baggage fee calculator shows the difference. If you know you will check a bag, see our guide to checked luggage size limits.
How to measure your bag
- Measure the packed bag, not the empty one — a full case bulges.
- Include wheels, handles and any external pockets at their furthest points.
- Compare all three dimensions against your airline’s limit, not just one.
- If you are between sizes, size down: gate agents round up, not down.
Frequently asked questions
What is the standard carry-on luggage size?
For most major US airlines the maximum carry-on size is 22 x 14 x 9 inches (56 x 36 x 23 cm), including wheels and handles. It is a widely used standard, but budget and international airlines are often smaller, so always check your specific airline.
Do wheels and handles count toward the carry-on size?
Yes. Airlines measure the bag at its largest points, so the wheels and the handles are included. A bag advertised as carry-on sized can still be refused if its wheels push it over the limit.
Does the TSA set carry-on size limits?
No. The TSA handles security screening, including the liquid rules, but it does not set the size of your carry-on bag. Each airline sets its own carry-on dimensions, which is why the limit changes depending on who you fly.
Is there a weight limit for carry-on luggage?
Most major US airlines do not impose a carry-on weight limit, only a size limit. Many international and budget airlines do set a carry-on weight limit, often around 7 to 10 kg, so check before you fly if you are travelling outside the US.
What happens if my carry-on is too big?
At the gate, an oversized bag is usually checked into the hold, sometimes with a fee, and you collect it at baggage claim. Gate agents may use a sizer box to check bags, especially on full flights.
Are international carry-on sizes smaller than US ones?
Often, yes. Many European and budget airlines allow a smaller cabin bag than the US 22 x 14 x 9 inch standard, and some split it into a small free bag and a larger paid one. Check the airline’s cabin bag dimensions before you pack.