Personal item size by airline, 2026

Last verified: September 2026. 

Frontier Airlines gives every ticket one free bag. It has to be 18 by 14 by 8 inches or smaller, and the measurement counts the wheels, the handles and the straps (Frontier Airlines bag options page, checked September 2026). A bag that fails the frame at the boarding door becomes a paid carry-on, and paying at that point runs to roughly $99 per direction (Open and Fair Skies Frontier fee guide, July 2026).

Twenty-one airlines are listed on this page and almost none of them agree with each other. United Airlines allows 10 inches of width where Frontier allows 14. Ryanair's free bag is 40 by 30 by 20 centimetres, which works out at 15.7 by 11.8 by 7.9 inches. Air Canada caps depth at 6 inches. Delta Air Lines, Southwest Airlines and Alaska Airlines publish no personal item dimensions at all.

What follows is the whole table, plus the fees that apply when a bag fails, the fare classes that quietly remove your overhead bin, and the aircraft where the space under the seat is smaller than the rule allows. Every figure carries its source and the month it was checked. The last two columns of each table show whether the two hard-sided TAKE OFF sizes clear that limit on paper.

What counts as a personal item

A personal item is the one free bag that has to fit fully under the seat in front of you, measured on the outside with wheels, handles, straps and stuffed pockets all counted. It is not the same as a carry-on, which goes in the overhead bin and costs money on every ultra-low-cost carrier in this guide.

The wheels are the part people miss. A suitcase sold as an 18-inch bag is usually 19 or 20 inches tall once its wheels are attached, and the metal frame at the gate has no opinion about which part of that is the suitcase. Frontier, United and Allegiant Air all print the phrase about handles and wheels in the same sentence as their numbers, so this is the rule as written rather than a strict reading of a vague one.

Weight is a separate question, and in the United States it is mostly theoretical. Frontier, Allegiant and JetBlue Airways publish no weight cap on the free personal item, and Frontier's 35-pound limit applies to the paid carry-on instead. Europe is different. Wizz Air caps its free bag at 10 kilograms and easyJet at 15, and both weigh bags far more often than any US carrier does (Lugg cabin luggage guide, 29 July 2026).

One more definition, because it causes arguments at the gate. A bag that does not fit under the seat is not automatically an oversized personal item. On most of these airlines it is reclassified as a carry-on, and you are charged the carry-on price at whatever the airport rate happens to be that day.

Personal item and carry-on limits, US airlines

Eleven US carriers are listed below. Seven publish a personal item limit as a set of numbers, three describe it only as a bag that fits under the seat, and Allegiant appears in circulation with two figures that contradict each other. All measurements are in inches and include wheels and handles.

Sources: Frontier Airlines bag options and optional services pages, checked September 2026; Packfits Allegiant page, 3 August 2026; Luggage Wiz personal item chart, August 2026; SkySonar personal item guide, 30 July 2026; SmarterTravel carry-on limits, January 2026; Travel Bag Insider US carry-on rules, August 2026. Fit columns are arithmetic against published limits, not photographed sizer tests.

Contour Airlines belongs in the same conversation and did not fit the table cleanly. Its personal item limit is 17 by 10 by 9 inches, the same narrow shape United uses, which catches wide backpacks the same way (Luggage Wiz, August 2026).

The four size profiles hiding in that table

Eleven airlines produce four shapes, not eleven. Once you know which profile you fly most often, buying a bag becomes a straightforward decision instead of a gamble against a chart. The profiles are the 18-inch group, the 17-inch group, the narrow-width group, and the carriers that publish nothing.

The 18 by 14 by 8 group is Frontier and American, and possibly Allegiant depending on which figure turns out to be current. This is the most generous published personal item in the United States and the size most personal item luggage is built to.

The 17-inch group is JetBlue, Breeze, Sun Country and Avelo, at either 17 by 13 by 8 or 17 by 13 by 9. Half an inch does not sound like a difference until you own a bag that is 17.5 inches long, at which point it is the whole difference.

The narrow group is United and Contour at 17 by 10 by 9. Ten inches of width rules out most hard-sided cases and a good number of backpacks, and it is the single most misread number in US baggage policy because travellers read the 17 and stop.

Then there is the group that publishes nothing. Delta, Southwest and Alaska describe the personal item as a bag that fits under the seat and leave it there. No number means no sizer to fail, and it also means a gate agent's judgement is the entire rule.

Where the published numbers disagree

Four of the eleven US carriers above cannot be quoted cleanly. Three publish nothing at all, and Allegiant circulates with two limits that produce opposite answers for the same bag. Any chart that hands all eleven a tidy number is filling gaps with guesses and hoping nobody checks.

Allegiant is the awkward one. Packfits lists the limit as 18 by 14 by 8 inches, checked 3 August 2026, and several airline guides say the same. Arca and Baggage Policies both give 7 by 15 by 16 inches, checked July and August 2026, which is an inch shallower and shorter on the long side. A bag measuring 17.5 by 13.5 by 7.8 inches clears the first figure and fails the second. The honest position is to check Allegiant's own baggage page for your travel date and pack to the smaller of the two.

Alaska is the second trap. The figure third parties cite is roughly 17 by 13 by 6 inches, and that 6-inch depth is shallower than anything else on this page. SkySonar reported in July 2026 that Alaska's customer service confirmed there is no official size chart at all, which means the number everybody quotes is an estimate that has been repeated until it looks official.

Delta and Southwest are easier to plan around than their silence suggests. Southwest publishes a physical description rather than a limit, and the under-seat space on its 737s measures roughly 18.5 inches wide by 8.5 inches tall, with about 14 inches of usable depth (Travel Beck Southwest under-seat guide, June 2026). That is a measurement of the aeroplane, not a rule, and it is more useful than a rule because the aeroplane does not negotiate.

What it costs when the bag fails

The fee is never the fee you saw at booking. Every airline on this page prices bags on a sliding scale that rises from booking to check-in to the gate, and the gate price is the one that hurts. Frontier's is roughly $99 per direction, and Allegiant charges $50 to $75 for an oversized personal item.

Sources: Frontier Airlines optional services, September 2026; Packfits and Baggage Policies Allegiant pages, August and September 2026; Newsweek airline fee roundup and American Airlines newsroom, April 2026; Travellon Ryanair guide, July 2026. Fees change without much notice, so treat these as the September 2026 position.

April 2026 is the reason the arithmetic changed. Delta, United, Southwest and American all moved the first checked bag to roughly $45 to $50 in the same month, with the third bag at $200 (Newsweek, April 2026). Southwest had already ended free checked bags for most fares on 28 May 2025. A family of four checking one bag each on a round trip now spends between $360 and $400 before anybody has eaten anything.

Against that, the free personal item is the only allowance nobody can price. It is included on every fare on every airline in this guide.

The fare class that removes your overhead bin

Basic economy is where size stops mattering and the fare takes over. On United's domestic basic economy tickets you get a personal item and nothing else, whatever your suitcase measures. Bring a roller to the gate on that fare and it goes in the hold at the checked-bag rate plus a handling charge.

The rest of the basic fares are more generous than most guides admit, and this is where a lot of published advice is out of date. JetBlue added a full carry-on back to Blue Basic for travel from 6 September 2024, and Delta and American both include a carry-on on their basic fares (Travel Vient basic economy guides, verified August 2026; SmarterTravel carry-on rules, January 2026). Several widely read charts still say all four restrict you to a personal item. They were right two years ago.

Two caveats keep that from being a green light. Basic fares board last, so on a full flight the bin above your row is already gone and the bag gets gate-checked anyway, and airlines revise these rules more often than they revise dimensions. Read the fare rules on the booking page rather than trusting any chart, including this one.

Frontier and Allegiant work differently again. Their base fares include only the personal item and the carry-on is a paid add-on regardless of status, which is the entire business model rather than a fare trap.

Europe runs on 40 by 30 by 20 centimetres

Ryanair and Wizz Air both give a free underseat bag of 40 by 30 by 20 centimetres, which converts to 15.7 by 11.8 by 7.9 inches. easyJet is the generous one at 45 by 36 by 20 centimetres, or 17.7 by 14.2 by 7.9 inches. A bag that fails the frame costs up to £70 or €75 at the gate.

Sources: Lugg UK cabin luggage guide, 29 July 2026; Travel Bag Insider Ryanair guide, May 2026; ATX Luggage cabin bag guide, May 2026.

Ryanair caps Priority boarding at about 95 passengers per flight, and on busy summer routes it sells out weeks ahead (Travellon Ryanair guide, July 2026). Once it is gone, overhead access is gone with it, and the 40 by 30 by 20 bag is the whole allowance. That is worth knowing before you book a fare on the assumption you can add the bigger bag later.

The European Parliament voted in January 2026 to make a free cabin bag law across the bloc, by 632 votes to 15, but the Council rejected the text and the file was still in conciliation with no agreement as of September 2026 (TripProf EU hand luggage summary, 2026). Headlines about a free cabin bag have been running for months. The rule is not in force, and travellers who assume it is are the ones paying at the gate.

Canada and Mexico

Canadian carriers publish the shallowest personal item limits in this guide. Air Canada and Porter Airlines both cap it at 17 by 13 by 6 inches, WestJet at 16 by 13 by 5.5, and Flair Airlines matches the 17 by 13 by 6 shape with a 7-kilogram weight limit on top. Six inches of depth excludes almost every rolling case.

Sources: U.N. Luggage Canada personal item guide, October 2025; CarrySizer Canadian carry-on rules, 19 June 2026; The Luggage Authority Air Canada guide, reviewed 22 July 2026; Baggage Policies Volaris page, August 2026; CarrySizer Avianca guide, 30 June 2026.

Volaris is the outlier in the other direction. Its 18 by 14 by 8 inch personal item is the most generous published allowance anywhere in this guide, and it applies on the Zero fare as well as the more expensive ones. For US to Mexico traffic that is the difference between packing a week into the free bag and paying at the counter in Tijuana.

Avianca weighs bags at check-in on domestic routes and enforces the 10-kilogram cabin limit more consistently than any US carrier does, according to CarrySizer's June 2026 guide. Weight, not size, is what catches people on Latin American carriers.

The space under the seat is not the same as the published limit

Airlines write one rule for a fleet of different aeroplanes. The physical cavity under the seat in front of you changes with the aircraft type, the row and whether you are at the window, and it is often smaller than the number on the baggage page.

Delta's own figures show the range. On a Bombardier CRJ200 the under-seat space is about 18 by 16 by 10.5 inches, while on an Embraer 175 it is about 17 by 16 by 7.8 inches (Clever Journey underseat guide, May 2026). Those two aircraft fly the same routes for the same airline under the same published policy. A bag that is 8 inches deep fits one and not the other.

The newer narrowbodies introduced a second problem. Southwest's 737 MAX 8 cabins put a power and entertainment box under alternating seats, which takes roughly 2 inches of width and 1.5 inches of height out of the cavity, and the middle seat can have two of them (Travel Beck, June 2026). A bag that slid under the seat on a 737-700 last year can wedge against a box on the MAX this year with no rule having changed at all.

Window seats are consistently the worst of the three. The curve of the fuselage eats into the space, and on an A320 the window position runs about an inch narrower than the aisle and middle. If your bag is at the limit and you have a seat choice, take the aisle.

Bulkhead rows have no under-seat space whatsoever, because there is no seat in front of you. On a personal-item-only fare that means your bag goes in the overhead bin for take-off and landing, which is usually fine, and occasionally is not when the bin is full.

Which TAKE OFF size clears what

The 18-inch Personal Item Suitcase 4.0 measures 17.5 by 13.5 by 7.8 inches with the wheels removed and 19.5 inches tall with them attached. One button is the difference between clearing an 18 by 14 by 8 frame and failing it. Wheels off, it clears Frontier, American and Volaris, and it is inside easyJet's free bag on paper.

It does not clear everything, and the tables say so. United's 10-inch width rules it out by three and a half inches. JetBlue, Breeze, Sun Country and Avelo sit at 17 or 13 inches on a side where the bag is 17.5 or 13.5, so it is over by half an inch in two places. Air Canada, WestJet, Porter and Flair cap depth at 6 inches or less, and no hard-sided rolling case gets under that. Ryanair and Wizz Air are out of reach for any 18-inch bag.

The 22-inch Carry-On 4.0 is a different case again. At 15.5 inches wide it is over the 22 by 14 by 9 standard that American, Delta, United, JetBlue, Alaska, Breeze and Sun Country publish, and it clears the wider 24 by 16 by 10 frames at Frontier and Southwest with the wheels on or off. It also lands inside the 55 by 40 by 23 centimetre Canadian carry-on limit with the wheels off, at 54.6 by 39.4 by 22.2 centimetres, which is close enough that a bulging front pocket would end the argument. Buying it as a universal carry-on would be a mistake. Buying it for Frontier, Southwest or a Canadian carrier is not.

How this actually gets enforced

Enforcement varies more than the numbers do. Frontier is the strictest active US carrier and uses a metal sizer at the boarding door, with roughly $99 per direction charged for a bag that fails (Camli Frontier rules page, August 2026). American and Delta are described as the most relaxed on personal items by Luggage Wiz, checked August 2026.

The trend is going the other way, though. United expanded automated bag sizers to more than 35 airports in late 2025 and is targeting over 80 by the end of 2026 (Travel Bag Insider, August 2026). Those scanners measure at the boarding gate and flag bags automatically, which removes the part of this system that has always favoured travellers: a busy agent who does not want the argument.

Allegiant flies a lot of small regional airports where agents have time to look at every bag, and physical sizers appear at its gates regularly (Arca, July 2026). Volume, not policy, is what makes a gate lenient.

Soft bags get away with more than hard ones. A squashy tote that is technically an inch over can be pushed into the frame and under the seat, while a hard shell either fits or does not. That is the honest trade. A hard case protects what is inside it and gives you no room to negotiate.

How to measure your bag the way the gate does

Pack the bag first, then measure it. Run the tape down the outside of the full bag from the top of the handle housing to the bottom of the wheels, across the widest point including any pocket that bulges, and front to back at the fattest part. That is the same measurement the frame takes.

A packed bag is usually half an inch fatter than an empty one, which is exactly the margin that decides most gate arguments. If the number you get is within half an inch of the airline's limit, treat it as over and repack rather than gambling on the agent.

Depth is the dimension worth writing down. It is where most rolling bags fail, it is the one people guess at instead of measuring, and it is the number that changes when you overstuff the front pocket. Eight inches is the US ceiling on most carriers, six inches is the Canadian one, and 20 centimetres is the European one.

Then check the airline's own page for your travel date. Every figure on this page was verified in September 2026 from the sources named under each table, airlines change these numbers without warning, and no single bag fits every airline on earth.

How this page is checked

Every row starts with the airline's own published baggage page where one exists. Where an airline publishes nothing, the row says so rather than borrowing a number from an aggregator and presenting it as policy, and the third-party figure is named as a third-party figure.

The fit columns are arithmetic, not photographs. They compare the published limit against dimensions in centimetres and inches for the two bags, and where a bag has not been photographed inside that airline's sizer the cell says on paper. Allegiant stays marked as not claimed until someone runs the test with a camera, which is the one row on this page that a photo would settle.

This page is reviewed on the first of each month, and dated changes are logged at the foot. If a figure here contradicts what an airline tells you at the counter, the airline is right and this page is out of date. Send the correction and it gets fixed the same week.