Carry On Bag Size for International Travel: What Size Is Allowed?

The widely accepted international carry-on target is about 22 x 14 x 9 inches — roughly 56 x 36 x 23 cm — measured with wheels and handles included.

A tape measure run along the outside of a packed bag, wheels and handle included, is where most gate-check surprises begin. That single measurement decides whether your bag rides in the overhead bin or gets tagged at the gate for a fee, and for international routes the number you need to hit changes the moment you cross into metric territory.

There is no single global standard. Airlines set their own limits, and the ones flying overseas tend to be stricter than the U.S. carriers you may be used to. Here’s what actually applies, carrier by carrier.

What Size Carry-On Is Actually Allowed?

Most U.S. airlines allow a carry-on up to 22 x 14 x 9 inches, while international carriers typically cap the larger cabin bag at roughly 55 x 40 x 20 cm. These are not the same bag — 22 inches equals about 56 cm, and a 9-inch depth equals about 23 cm, so a bag that clears Delta can still miss a Ryanair sizer by a centimeter or two.

That figure is a guideline for most airlines rather than a law, and it lines up neatly with the 22 x 14 x 9 shape: 22 + 14 + 9 = 45.

The confusion comes from two overlapping systems. U.S. carriers quote inches; European and Asian carriers quote centimeters. A bag built to the U.S. benchmark often measures 56 x 36 x 23 cm — four centimeters too wide and three too deep for a Ryanair 55 x 40 x 20 cm limit.

Airline Carry-On Limits at a Glance

U.S. legacy carriers cluster tightly around 22 x 14 x 9 inches, but Southwest, Spirit, and Frontier each go their own way —

Notice how easyJet’s 56 x 45 x 25 cm allowance is unusually generous for Europe, while Ryanair’s 55 x 40 x 20 cm sits at the tighter end. If you fly both on one trip, you pack to the smaller one.

If you’re shopping for a bag that clears the tighter European sizers without a fight, this roundup of tested carry on bags for international travel compares the dimensions that actually pass at the gate.

Where Most Travelers Get the Measurement Wrong

The most common error is measuring the interior cavity instead of the whole bag, wheels and handles included. Airlines measure the exterior, so a bag listed as “22 inches” internally can measure closer to 24 once the wheels are counted.

Weight is the second trap. U.S. carriers rarely weigh a carry-on, but international airlines often do, and a 10 kg cap applies faster than most people expect once a laptop and toiletries are inside. Personal items are a separate category with their own smaller limits, and they go under the seat, not in the bin.

• Measure the full exterior with a tape, not the inside lining.
• Check the weight limit before you pack, not at the gate.
• Treat the overhead carry-on and the under-seat personal item as two different bags with two different rules.

The FAA’s baggage guidance for travelers stays deliberately general on this point, which is why the airline’s own page is the only authority worth trusting on the day you fly.

Frequently Asked Questions

Do international airlines use inches or centimeters?

Most non-U.S. carriers publish limits in centimeters, and a few convert to inches for their English pages. A bag that matches the U.S. 22 x 14 x 9 target measures about 56 x 36 x 23 cm — slightly wider and deeper than many European limits, so it can still fail a Ryanair sizer.

Is there one carry-on size that works on every airline?

No. Sizing to the strictest common limit — roughly 55 x 40 x 20 cm, or about 21.5 x 15.5 x 8 inches — clears the widest range of carriers, including the tight European ones. Anything larger risks a gate check on at least one leg of a multi-airline trip.

Are carry-on weight limits common on international flights?

U.S. carriers rarely enforce a weight limit, which is why travelers switching to a foreign airline often get caught off guard at the gate.