How to Choose a Carry-On Suitcase: Size Limits, Weight and Materials (What to Check)

A carry-on suitcase is one of the few travel purchases where a single inch matters. Too big and you pay to check it at the gate; too small and you end up buying a second bag. Prices run from budget softside cases to hardside models costing several hundred dollars, and product photos make most of them look the same. This guide covers what to compare before you buy, whatever brand you choose.

Start with your airline's size limit

Every airline publishes its own cabin baggage limit, usually as height x width x depth including wheels and handles. Many large US carriers use about 22 x 14 x 9 inches, but regional airlines, budget carriers and many international airlines set smaller limits or add a weight cap.

• Use exterior dimensions. Look for measurements that include wheels and handles. Some listings quote the body only, which can understate height by an inch or more.
• Check weight limits. Some international airlines cap carry-on weight at around 7 to 10 kg (15 to 22 lb). A heavy empty case leaves less room for your things.
• Watch the "bigger carry-on" label. Many brands sell a slightly larger carry-on that fits some airlines but not others. If it is taller than your airline's limit, plan on checking it.
• Expansion counts. An expandable case usually meets cabin limits only when it is zipped closed.

Compare capacity in liters, not just inches

Two cases with similar outside dimensions can hold quite different amounts. Interior shape, the wheel housing and the handle system all take up space. Capacity in liters is the easiest way to compare: a standard domestic carry-on often lands somewhere around 35 to 45 liters, and larger "bigger" carry-ons around 45 to 50. Interior dimensions also help if you pack with cubes. Organization matters too: compression panels, divided clamshells and outward-opening lids change how much you can fit and how easily you can find it. A case that opens like a book with two equal halves suits folded clothes, while a single deep compartment with a flat lid handles bulky shoes and toiletry bags better.

Choose a shell: polycarbonate, aluminum or softside

• Polycarbonate hardside is light, flexes under impact and is the most common material on mid-range and premium cases. It scuffs, but usually does not crack.
• ABS hardside is cheaper and stiffer but more likely to crack. Blends of ABS and polycarbonate fall in between.
• Aluminum or aluminum-framed cases look sharp and close with latches instead of a zipper, but they are heavier, dent visibly and often hold less.
• Softside nylon or polyester cases are lighter, often have exterior pockets and can squeeze into tight bins, but offer less protection for fragile items.

Check wheels, handle and lock

Four 360° spinner wheels are easiest on smooth airport floors, while two-wheel inline cases roll better on cobblestones and lose less interior space. Look for recessed or replaceable wheels, a telescoping handle that locks at more than one height without wobbling, and a TSA-accepted lock so security can open it without breaking it. Extras such as wheel brakes, a hook for a second bag, a laptop sleeve or a hidden pocket for a Bluetooth tracker are useful but not essential.

Read the warranty and return terms

Luggage warranties vary more than most buyers expect. Some brands repair airline damage; others cover only manufacturing defects. Check:

• How long free repairs last and whether airline handling is covered
• Whether the brand replaces a case it cannot repair, and how many times
• Whether cosmetic scuffs, dents and lost bags are excluded (they usually are)
• Who pays shipping for a repair
• How long you have to return an unused case, and whether personalized cases or sale items are final

A long return window is useful only if you test the case at home before you travel. Pack it fully, roll it around indoors and keep the packaging. For an example of how one direct-to-consumer brand handles sizes, returns and repairs, see our Away review.

Decide how much to spend

A cheaper case can be fine for a few trips a year, especially if it meets your airline's limit and has decent wheels. Paying more tends to buy a better handle and wheels, lighter materials and a stronger repair program. Bundles and seasonal sales can bring premium cases closer to mid-range prices, and some brands offer verified discounts for students, teachers, medical workers or military members.

It also helps to think about the whole set rather than one case. If you mostly take long-weekend trips, a standard carry-on plus a personal item such as a backpack or tote may cover nearly everything, and a checked size can wait. If you travel for a week or more, or with family, a medium checked case may be the better first purchase, with a carry-on added later. Buying pieces from the same line can make sense for matching looks and shared spare parts, but there is no need to buy a full matching set if you will only use one size.

Finally, read recent owner reviews for the specific model rather than the brand in general. Comments about wheels wearing out, zippers splitting or handles sticking tend to show up within the first year of use, and they tell you more than marketing claims about durability.

A quick checklist

• Exterior dimensions, including wheels and handles, within your airline's limit
• Empty weight and any carry-on weight cap
• Capacity in liters and the interior layout
• Shell material that suits how you travel
• Spinner or inline wheels, a stable handle and a TSA-accepted lock
• Repair coverage for airline damage, and how long it lasts
• A return window long enough to test the case at home, with exclusions noted