All passengers flying with European low-cost carriers (LCCs) are subject to carry-on rules, but American travelers are particularly vulnerable because of differing expectations.
European LCCs such as Ryanair, EasyJet, and Wizz Air are rigorously enforcing "gate sizers," imposing fines of up to $95 for bags that exceed their strict dimensions by even an inch.
What Is Happening at European Gates?
European low-cost airlines have long-standing, stringent rules regarding cabin baggage, often differentiating between a small personal item (free) and a larger cabin bag (requiring a fee or specific fare).
Passengers whose bags fail to meet the airline's sizing requirements may be charged on the spot, with no grace period for non-compliance.
Ryanair's bag rules permit one small personal bag (40 x 30 x 20 cm) for free, which must fit under the seat. That is about 15.7 x 11.8 x 7.9 inches.
A larger 10kg cabin bag (55 x 40 x 20 cm) requires purchasing 'Priority & 2 Cabin Bags.' That size is about 21.7 x 15.7 x 7.9 inches, up to about 22 pounds.
If a bag exceeds the free allowance or a larger bag is brought without priority, a gate fee of €/£46 to €/£60 can apply. That is roughly $50 to $76. Ryanair warns that the bag may be refused or placed in the hold, where available.
For larger or oversize bags brought to the gate (over 55 x 40 x 20 cm), fees can rise to €70 to €75. That is roughly $76 to $95.
EasyJet's cabin-bag rules start with one free small cabin bag: 45 x 36 x 20 cm. That is about 17.7 x 14.2 x 7.9 inches. It must fit under the seat and weigha maximum of 15 kg, about 33 lb.
The large cabin bag (up to 56 x 45 x 25 cm) is a paid add-on. That is about 22.0 x 17.7 x 9.8 inches. It goes in the overhead locker. The weight limit is also 15 kg, about 33 lb.
On easyJet's fees table, a large cabin bag starts from €7.99, or roughly $9. However, for travelers who show up at the gate with a bag that violates the rules, the fees jump. EasyJet lists a fee of €58, roughly $63, per item for oversized cabin bags or any non-purchased bag brought to the gate beyond your allowance.
Wizz Air passengers are entitled to one free small cabin bag per passenger that fits under the seat. The maximum size is 40 x 30 x 20 cm, about 15.7 x 11.8 x 7.9 inches. Weight limit is 10 kg (about 22 lbs).
To bring a larger cabin bag, passengers must purchase 'WIZZ Priority' or book it as part of a fare bundle like 'WIZZ Go' or 'WIZZ Plus.' The larger bag size is 55 x 40 x 23 cm (about 21.7 x 15.7 x 9.1 inches) and also weighs up to 10 kg (22 lbs).
Wizz Air's airport baggage fee for a 20 kg checked bag in low season ranges from €70 to €80 per flight, per passenger, per bag.
That equals approximately $76 to $87.
What Does This Mean For U.S. Carry-Ons?
Standard United's carry-on limit is 22 x 14 x 9 inches, which is not a guaranteed 'safe size' for Europe's low-cost carriers.
It will fit easyJet's paid overhead-bag allowance and usually aligns with Wizz Air and easyJet limits of 9.1 in and 9.8 in depth, respectively.
However, it can still fail Ryanair's cabin-bag depth of 7.9 inches. That one-inch difference is exactly the kind of detail that may trigger additional bag fees at the gate.
An even bigger surprise is the 'personal item.' United allows an under-seat bag up to 17 inches long, while Ryanair and Wizz Air cap the free under-seat bag at roughly 15.7 inches in height, with similarly tight dimensions overall.
American Airlines' personal item limit of 18 x 14 x 8 inches is more generous in height and width than United's 17 x 10 x 9 inches.
Compared to European low-cost carriers, AA's allowance is significantly larger than the free under-seat limits on Ryanair and Wizz Air, which cap personal items at 15.7 x 11.8 x 7.9 inches.
It means a U.S.-standard backpack or laptop bag that passes on United can still be ruled oversized at a European gate.