Spirit, Frontier, Allegiant and American all cap a personal item at 18 x 14 x 8 inches. Breeze and JetBlue allow 17 x 13 x 8, Avelo and Sun Country 17 x 13 x 9, and United only 17 x 10 x 9. Delta, Southwest, Alaska and Hawaiian publish no personal-item dimensions at all.
We pulled every number below from each airline's own website in October 2026. Two extra columns show where our Air Pro vacuum compression backpack lines up in its 17-inch and 19-inch sizes. Those two columns are math on published numbers, not a test in any airline's sizer.
Personal item and carry-on size limits by airline (checked Oct 2026)
Sizes are length x width x depth as each airline lists them. Spirit and Frontier count handles and wheels (Frontier adds straps), so measure your bag that way everywhere. A star (*) means the airline lists inches only and we converted to centimeters.
| Airline | Personal item limit | Carry-on limit | Free carry-on on cheapest fare? | Air Pro 17-inch fits (by published dimensions) | Air Pro 19-inch fits | Official page (checked Oct 2026) |
|---|---|---|---|---|---|---|
| Spirit | 18 x 14 x 8 in (45 x 35 x 20 cm) | 22 x 18 x 10 in (56 x 46 x 25 cm) | No (Value). Included in Premium Economy and Spirit First | Yes, as personal item | Carry-on only | Spirit bag info |
| Frontier | 18 x 14 x 8 in (46 x 36 x 20 cm*), up to 35 lb | 24 x 16 x 10 in (61 x 41 x 25 cm*), up to 35 lb | No. Included in Economy, Premium and Business bundles | Yes, as personal item | Carry-on only | Frontier bag options |
| Allegiant | 18 x 14 x 8 in (45 x 35 x 20 cm) | 22 x 16 x 10 in (55 x 40 x 25 cm) | No (fee varies by route) | Yes, as personal item | Carry-on only | Allegiant fees |
| Breeze | 17 x 13 x 8 in (43 x 33 x 20 cm*) | 22 x 14 x 9 in (56 x 36 x 23 cm*), up to 35 lb | No (paid or in bundles) | Yes, as personal item (0 in spare on length) | Carry-on only | Breeze bag allowance |
| Sun Country | 17 x 13 x 9 in (43 x 33 x 23 cm*) | 24 x 16 x 11 in (61 x 41 x 28 cm*), up to 35 lb | Contract says fees may apply | Yes, as personal item (0 in spare on length) | Carry-on only | Sun Country contract of carriage (Oct 15, 2025 edition) |
| Avelo | 17 x 13 x 9 in (43 x 33 x 22 cm) | 22 x 14 x 9 in (55 x 35 x 22 cm) | No (paid extra) | Yes, as personal item (0 in spare on length) | Carry-on only | Avelo carry-on bags |
| American | 18 x 14 x 8 in (45 x 35 x 20 cm) | 22 x 14 x 9 in (56 x 36 x 23 cm) | Yes (Basic Economy) | Yes, as personal item | Carry-on only | American carry-on |
| United | 17 x 10 x 9 in (43 x 25 x 22 cm) | 22 x 14 x 9 in (56 x 35 x 23 cm) | No on most routes (Basic Economy). Yes to South America, transatlantic, transpacific | No (width 12.6 in vs 10 in); fits as carry-on | Carry-on only | United carry-on bags |
| Delta | None published (under the seat) | 22 x 14 x 9 in (56 x 35 x 23 cm) | Yes, no Basic exception listed on the pages we checked | No size published; fits as carry-on | Carry-on only | Delta carry-on |
| Southwest | None published (under the seat) | 24 x 16 x 10 in (61 x 41 x 25 cm*) | Yes, no fare exception listed | No size published; fits as carry-on | Carry-on only | Southwest carry-on policy |
| JetBlue | 17 x 13 x 8 in (43 x 33 x 20 cm) | 22 x 14 x 9 in (56 x 36 x 23 cm) | Yes (Main Base and up) | Yes, as personal item (0 in spare on length) | Carry-on only | JetBlue carry-on bags |
| Alaska | None published (under the seat) | 22 x 14 x 9 in (56 x 36 x 23 cm*) | Yes (Saver) | No size published; fits as carry-on | Carry-on only | Alaska carry-on |
| Hawaiian | None published (shared Alaska/Hawaiian page) | 22 x 14 x 9 in (56 x 36 x 23 cm*) | Not stated on pages we could open | No size published; fits as carry-on | Carry-on only | Hawaiian carry-on |
| Air Canada | 17 x 13 x 6 in (43 x 33 x 16 cm) | 21.5 x 15.5 x 9 in (55 x 40 x 23 cm) | No on Economy Basic within North America and the Caribbean | No (depth; see note); fits as carry-on | Carry-on only | Air Canada carry-on |
| WestJet | 16 x 13 x 6 in (41 x 33 x 15 cm) | 22 x 14 x 9 in (56 x 36 x 23 cm) | No on UltraBasic (except Europe, Asia) | No (length); fits as carry-on | Carry-on only | WestJet carry-on |
| British Airways | 16 x 12 x 6 in (40 x 30 x 15 cm) | 22 x 18 x 10 in (56 x 45 x 25 cm) | Yes (Economy Basic) | No (length); fits as carry-on | Carry-on only | British Airways baggage |
| Lufthansa | 15.7 x 11.8 x 5.9 in* (40 x 30 x 15 cm) | 21.7 x 15.7 x 9.1 in* (55 x 40 x 23 cm), up to 8 kg | No on short/medium-haul Economy Basic; long-haul not stated | No (length); fits as carry-on | Carry-on only | Lufthansa carry-on |
| Aer Lingus | 15.5 x 11.5 x 8 in (40 x 30 x 20 cm) | 21.5 x 15.5 x 9.5 in (55 x 40 x 24 cm), up to 10 kg | Yes on North America flights | No (length); fits as carry-on | Carry-on only | Aer Lingus baggage |
Note on Air Canada: the Air Pro's slimmest published depth is 6 inches, which matches Air Canada's limit on paper. We still mark it "No" because the bag expands to 8 inches, and any packing past the slimmest setting puts it over.
What is the standard personal item size on US airlines?
There isn't one standard. The closest thing is 18 x 14 x 8 inches, which is the published limit on Spirit, Frontier, Allegiant and American. A second group sits one size down at 17 x 13 inches, with 8 inches of depth on Breeze and JetBlue and 9 inches on Avelo and Sun Country.
United is the outlier. Its 17 x 10 x 9 limit is 4 inches narrower than the 18 x 14 x 8 group.
Abroad, limits shrink. British Airways and Lufthansa allow 40 x 30 x 15 cm, WestJet 41 x 33 x 15 cm and Air Canada 43 x 33 x 16 cm.
Which airlines don't publish a personal item size?
Delta, Southwest, Alaska and Hawaiian only say the item has to fit under the seat in front of you. Southwest names examples (purse, briefcase, laptop case, backpack), and Alaska says "a purse, briefcase or laptop bag."
In practice the seat sets the rule, and under-seat space changes from plane to plane.
Does the cheapest fare include a free carry-on?
On Spirit, Frontier, Allegiant, Breeze and Avelo, no. The same goes for United Basic Economy on most routes, Air Canada Economy Basic within North America and WestJet UltraBasic. On those fares the personal item is your only free bag, so its size decides what you can bring.
American Basic Economy, JetBlue Main Base, Alaska Saver and Southwest all include a carry-on, and Delta lists no Basic exception. On those airlines a bag that's too big for the floor can usually go overhead instead.
Which Air Pro size fits which airline?
The 17-inch Air Pro measures 17 x 12.6 x 6 to 8 inches (43 x 32 x 15 to 20 cm). By published dimensions it is within the personal-item limit on 8 of the 18 airlines above: Spirit, Frontier, Allegiant, American, Breeze, JetBlue, Avelo and Sun Country. On the last four, its length matches the limit exactly.
It doesn't meet United's 10-inch width or the 40 cm limits of British Airways, Lufthansa and Aer Lingus. It fits every carry-on limit in the table.
The 19-inch Air Pro (19 x 12.6 x 6 to 8 inches, 49 x 32 x 15 to 20 cm) is a carry-on bag. Its length puts it over every published personal-item limit.
One verified buyer, Joel P., wrote that he took the 19-inch on a short trip to Miami and "it fit perfectly under the airplane seat." That can happen, since under-seat space varies by aircraft. But on an airline that publishes a personal-item size, a 19-inch bag is over the limit on paper, and the gate agent gets the final say.
Both sizes start at $149 and come with the rechargeable pump in the box.
How we compared (methodology)
This is a spec comparison, not a gate test. Here's exactly what we did:
- We read each airline's own baggage page (or its contract of carriage when the bag page wouldn't load) in October 2026.
- We matched the bag's longest side to the limit's longest side, and so on down. A bag "fits" only if all three measurements are at or under the limit.
- We counted the Air Pro at its full 8-inch depth, because that's the deepest it gets when packed.
- Where an airline gives only inches, we converted to centimeters at 2.54 cm per inch and rounded. Those cells carry a star.
- Where an airline publishes no personal-item size, we wrote "None published" instead of guessing.
Flovir sells the Air Pro, so read the two bag columns with that in mind. Limits change and fares get renamed (JetBlue's Blue Basic is now Main Base), so check your own booking before you pack.
What the numbers don't tell you
Frontier's page says the size of your personal item "will be checked during boarding." Breeze says airport team members make the final call. Spirit refers to a "sizer bin," and United says you can use its bag sizers at the airport.
A soft backpack also bulges when stuffed, and depth is the tightest number on an 18 x 14 x 8 limit. Our guide to fitting a vacuum backpack into 18 x 14 x 8 covers how compression helps there.
Compression has real downsides too. Weight doesn't drop, so Frontier's 35-pound personal-item limit still applies, and some fabrics come out wrinkled. You need the pump to reseal the bag on the way home, and getting one shirt out means opening the whole sealed compartment.
Who this chart is not for
If you mostly fly United Basic Economy or short European hops on basic fares, the 17-inch Air Pro is too big for the personal-item limit, and a slimmer bag will serve you better. If you need wheels or a bag under 3 pounds, a 3.5 to 4 pound backpack isn't the right pick either.
Airline-specific guides with more detail: Spirit personal item size, Frontier personal item size and vacuum-sealed bags at TSA.
Not sure your bag qualifies at all? Start with what counts as a personal item, including the items most airlines let you bring on top of it.
FAQ
What is the most common personal item size?
18 x 14 x 8 inches (45 x 35 x 20 cm). Spirit, Frontier, Allegiant and American all use it as of October 2026. Breeze, JetBlue, Avelo and Sun Country use a slightly smaller 17 x 13 inch limit.
Is a backpack a personal item?
Yes, if it meets the size limit. Spirit and Frontier list small backpacks as examples, and Southwest names backpacks too.
Does Delta have a personal item size limit?
Delta publishes no dimensions. Its carry-on page says the item should fit under the seat in front of you, such as a purse or laptop bag.
Can a 19-inch backpack be a personal item?
Not on any airline in our table that publishes a size. The longest limit we found is 18 inches. On airlines with no published size, it depends on the space under the seat and the agent at the gate.
If one bag for every airline on this list matters to you, compare the two sizes on the Air Pro product page before you buy.