Carry-On Size Guide

Most major US airlines allow a carry-on up to 22 x 14 x 9 inches, including wheels and handles. The common international guideline is 115 cm, or 45 linear inches, total. Allowances change without much notice, so the airline's own site is always the final word before you fly.

The 115 cm rule, explained

The number behind most carry-on limits is an IATA guideline: a cabin bag should total no more than 115 cm, about 45 linear inches, when you add length, width, and depth together. Airlines are free to set their own limits, and most do, but nearly all of them land near that total. The standard US allowance of 22 x 14 x 9 inches adds up to exactly 45 linear inches, which is not a coincidence.

Linear inches are a useful sanity check, but individual dimensions still matter. A bag that totals 45 inches in a shape the sizer does not accept can still be refused, so measure all three dimensions, not just the sum.

Wheels and handles count

This is the detail that catches most people. Airline limits describe the total space your bag occupies, so wheels, feet, bumpers, and the handle housing all count toward the measurement. A case sold as "22 inches" sometimes means a 22-inch shell with wheels adding more on top, which is how a nominally compliant bag fails the sizer at the gate.

When you compare cases, look for the overall dimensions including wheels and handles. If a brand only lists shell dimensions, assume the true size is larger.

US airline carry-on size limits

The majors cluster around one standard, with the low-cost carriers running their own numbers:

Airline	Max carry-on size
American	22 x 14 x 9 in
Delta	22 x 14 x 9 in
United	22 x 14 x 9 in
Alaska	22 x 14 x 9 in
JetBlue	22 x 14 x 9 in
Hawaiian	22 x 14 x 9 in
Southwest	24 x 16 x 10 in
Spirit	22 x 18 x 10 in
Frontier	24 x 16 x 10 in

All figures include wheels and handles, and all of them can change. Verify on the airline's site before you fly, especially if your bag is close to the limit.

Flying internationally? Expect smaller and weighed

International carriers are often stricter in two ways. First, the size limit is frequently smaller: 55 x 40 x 23 cm is a common European standard, and it is tighter than the US allowance in width. A bag built to the US standard may not fit some international sizers, so check before a trip abroad.

Second, many international airlines cap carry-on weight, commonly somewhere between 7 and 12 kg (roughly 15 to 26 lb), where most US majors publish no domestic weight limit at all. Weight catches travelers off guard more often than size does on international itineraries. We break the numbers down by airline in our guide to carry-on weight limits.

How to measure your own bag

Do it the way the airline does:

1. Stand the bag upright on a hard floor, as it would sit in a sizer.
2. Measure height from the floor, including the wheels, to the top of the bag or the retracted handle, whichever is higher.
3. Measure width and depth at the widest points, including any bumpers, feet, or pockets that stick out.
4. Measure it packed, not empty. Soft-sided and expandable bags bulge when full, and the bulge counts. Hard-shell cases hold their dimensions, which is one of their quiet advantages here.

If any dimension is within half an inch of the limit, treat the bag as borderline and pack accordingly.

What happens if your bag is oversize

At the gate, agents can ask any bag that looks large to go in the metal sizer. If it does not fit, the bag gets gate-checked. On a standard fare that is usually free but means waiting at the carousel. On basic economy fares, and on most low-cost carriers, a gate-checked bag can come with a fee that is often higher than the price of checking it in advance. Spirit and Frontier in particular price gate-side bag fees well above their online rates.

The cheapest oversize bag is the one you catch at home with a tape measure.

Basic economy caveats

A full-size carry-on is not always included in the ticket. Basic economy fares on some US carriers, and standard fares on most ultra-low-cost carriers, include only a personal item that fits under the seat, with the overhead bag sold separately. Before assuming your case flies free, check what your specific fare includes. If you are weighing whether you can travel on the small bag alone, our guide to personal item versus carry-on covers the trade-offs.

Getting the most from the size you have

Once your bag clears the sizer, the game becomes using the space well. Packing method matters more than most gear: rolling versus folding, keeping heavy items over the wheels, and leaving room so the case closes without force. We walk through the full method in how to pack a carry-on.

Common questions

Do wheels really count toward carry-on size?

Yes. Airline limits describe total occupied space, and the sizer at the gate does not make exceptions for wheels or handles. Always compare overall dimensions, not shell dimensions, when shopping.

Is a 22 x 14 x 9 bag guaranteed to fly as a carry-on?

On the major US carriers, a bag at or under 22 x 14 x 9 inches meets the published limit. Nothing is guaranteed forever, though: allowances change, and very full flights sometimes gate-check compliant bags for space. Check your airline before each trip.

What is the carry-on weight limit in the US?

Most US majors publish no carry-on weight limit for domestic flights; if you can lift it into the bin, it flies. International carriers commonly cap cabin bags at 7 to 12 kg, so weigh your packed bag before flying abroad.

Will a US-size carry-on work in Europe?

Often, but not always. A common European standard is 55 x 40 x 23 cm, which is narrower than the US allowance. Some European carriers accept US-size bags, others do not, so check the specific airline before an international trip.

What if my bag is half an inch over?

It might fly for years without a problem, and it might get pulled at the gate tomorrow. Sizers and enforcement vary by airport and agent. If you fly often, a bag comfortably inside the limit removes the gamble.

A carry-on built to the standard

The TALO 20" Carry-On is built to standard cabin sizing for major US airlines, with a rigid aluminum shell that holds its dimensions no matter how full it is, so what you measure at home is what shows up at the sizer. Exact dimensions are listed on the product page.