Frontier's personal item can be up to 18 x 14 x 8 inches, including handles, wheels and straps, and can weigh up to 35 pounds. It's free and goes under the seat in front of you. Frontier checks the size during boarding, and a carry-on (24 x 16 x 10 inches) is not in the base fare.
That's from Frontier's own bag page, checked in October 2026. If you want a backpack built around that limit, the 17-inch Air Pro vacuum backpack is within it by published dimensions, while the 19-inch is carry-on size.
What are Frontier's personal item and carry-on limits?
| Bag | Maximum size | Maximum weight | Included in the base fare? |
|---|---|---|---|
| Personal item | 18 x 14 x 8 in (about 46 x 36 x 20 cm), handles, wheels and straps included | 35 lb | Yes |
| Carry-on bag | 24 x 16 x 10 in (about 61 x 41 x 25 cm), handles, wheels and straps included | 35 lb | No. Included in the Economy, Premium and Business bundles |
Source: Frontier Bag Options, checked October 2026. Frontier lists inches only, so the centimeters are our conversion.
Elite status changes the picture. Frontier's page lists a carry-on for Elite Gold members, and a carry-on plus checked bags for Elite Platinum and Elite Diamond.
Why the word "straps" matters on Frontier
Frontier's wording is "including handles, wheels, and straps." Spirit's page names handles and wheels but doesn't mention straps.
For a backpack that's a real detail, because shoulder straps and a loose waist belt hang off the back and add depth. Tighten them or clip them flat before you board.
Loose straps on a bag that's already at 8 inches can be the half-inch that puts it over.
Does Frontier check your personal item at the gate?
Yes. Frontier says the size of your personal item will be checked during boarding, and items larger than the allowed size are subject to an additional charge. The page doesn't give the amount or describe a sizer.
It does say bag prices at the airport are higher than when you add them online. If you think your bag might not pass, adding a carry-on while booking is the cheaper move.
What counts as a personal item on Frontier?
Frontier's examples are purses, small backpacks and laptop bags. One item, under the seat, inside 18 x 14 x 8 inches and 35 pounds.
A backpack is fine. Measure it packed, with the straps where they'll be when you walk on, and with anything in the side pockets.
Does the 35-pound limit matter?
For most people, no. A tightly packed 18 x 14 x 8 bag of clothes rarely gets near 35 pounds. Where it can matter is with dense items: shoes, a laptop, chargers, books, toiletries.
It also matters with compression. Squeezing the air out of clothes lets you fit more in the same box, and every extra item still adds weight. A bathroom scale before you leave settles the question.
What fits in Frontier's personal item for 3, 5 or 7 days?
The 18 x 14 x 8 box is 2,016 cubic inches, about 33 liters. Here is general packing advice, not a test result.
3 days
Usually doable in any bag that meets the limit. Wear your bulkiest layer, pack two tops and one spare bottom, and use travel-size toiletries.
5 days
Choose clothes that mix and match so each piece gets worn twice. Pack one pair of shoes besides the ones on your feet, at most.
7 days
Plan a sink wash or a laundromat stop, or reduce the space your clothes take. Compression cubes and vacuum compartments both do that, with different trade-offs. We compare them in compression cubes vs vacuum bags vs a vacuum backpack.
Which Air Pro size fits Frontier's personal item limit?
This compares published numbers only. We have not put either bag in a Frontier sizer.
| Air Pro size | Published dimensions | Frontier personal item (18 x 14 x 8 in, 35 lb) | Frontier carry-on (24 x 16 x 10 in) |
|---|---|---|---|
| 17-inch | 17 x 12.6 x 6 to 8 in, 3.5 to 4 lb empty | Within the limit. Depth at full expansion equals the 8 in limit | Within the limit |
| 19-inch | 19 x 12.6 x 6 to 8 in, 3.5 to 4 lb empty | Over by 1 inch of length | Within the limit (needs a carry-on or bundle) |
With the 17-inch, keep the straps snug and the outside pockets flat, since Frontier counts straps and the bag has no spare depth at full expansion. Weight isn't the issue: the bag starts at 3.5 to 4 pounds, which leaves about 31 pounds for what you pack.
The 19-inch belongs in the overhead bin on Frontier. It makes sense if you book a bundle with a carry-on anyway.
Both start at $149. The rechargeable pump is in the box, and returns are accepted for 90 days after delivery if the bag is unused.
Frontier vs Spirit personal item rules
| Rule | Frontier | Spirit |
|---|---|---|
| Personal item size | 18 x 14 x 8 in | 18 x 14 x 8 in |
| Straps counted | Yes, named on the page | Handles and wheels named |
| Personal item weight limit | 35 lb | None listed |
| Carry-on size | 24 x 16 x 10 in | 22 x 18 x 10 in |
| Carry-on in the cheapest fare | No | No (Value) |
Both checked October 2026. Full details for Spirit are in our Spirit personal item guide, and every airline we checked is in the personal item size by airline chart.
The honest downsides of vacuum compression
Compression saves space and nothing else: weight stays the same, and some fabrics wrinkle. You need the pump to repack before the flight home, and the sealed compartment has to be opened to take out a single item. If you want to grab clothes during the trip without unsealing, keep a day's outfit in the outside pocket.
Who this isn't for
If you always buy a Frontier bundle with a carry-on, a standard roller bag will do, and you don't need to fight for the 8-inch depth. If you need wheels, or a bag that weighs under 3 pounds, the Air Pro isn't the right choice either.
FAQ
How strict is Frontier about personal item size?
Frontier says it checks the size during boarding and charges for items over the limit. We can't speak to how often that happens on a given flight. Packing to the exact limit avoids the question.
Is a backpack a personal item on Frontier?
Yes. Small backpacks are one of Frontier's own examples, as long as the bag is within 18 x 14 x 8 inches with straps and 35 pounds.
Does Frontier's personal item size include straps?
Yes. Frontier's page says the limit includes handles, wheels and straps.
Is Frontier's carry-on bigger than Spirit's?
Longer, yes: 24 x 16 x 10 inches on Frontier against 22 x 18 x 10 on Spirit. Spirit's is wider.
To see both Air Pro sizes side by side, visit the Air Pro product page.