Does a Backpack Count as a Personal Item?

American Airlines and Allegiant both cap the personal item at 18 x 14 x 8 inches. United allows 9 x 10 x 17 inches, and JetBlue allows 17 x 13 x 8 inches, both close cousins of American's number. Air Canada's limit is 17 x 13 x 6 inches, and Avelo allows 17 x 13 x 9 inches.

Air France runs smaller and stricter, 16 x 12 x 6 inches, and folds the personal item's weight into the same combined cap as the carry-on rather than giving it its own weight allowance. Across this group, the tightest published number is Air France's, and the roomiest is American's or Allegiant's.

It's worth noticing how tightly clustered most of these numbers actually are: American, Allegiant, JetBlue, Air Canada, and Avelo all sit within about an inch or two of each other on every dimension, suggesting a rough industry convention even without a formal standard. Air France and United are the two outliers, one smaller, one shaped differently, wider and shorter rather than taller.

Delta, Alaska, and Southwest all allow a personal item, purses, briefcases, laptop bags, small backpacks, but none of them publish a numeric size limit for it. Delta's own guidance simply lists acceptable item types; it doesn't attach inches or centimeters to any of them.

That's not an oversight, it's a deliberate choice these airlines have made, and it means the honest answer for how big can a personal item be on Delta, Alaska, or Southwest is there's no published number, only a fit-under-the-seat test applied at the gate agent's discretion.

That silence isn't unique to personal items either. Delta, Alaska, and Southwest also decline to publish an official carry-on weight limit, relying instead on a fit-and-lift test enforced at the gate. It's a pattern worth recognizing: these three airlines consistently favor qualitative descriptions over hard numbers across multiple parts of their baggage policy, not just the personal item.

Southwest's own guidance does describe the personal item, alongside the carry-on, as needing to fit in the space provided under the seat or in the bin, without quantifying either allowance beyond that shared, qualitative standard, reinforcing that this is a consistent policy choice across Southwest's baggage rules generally, rather than an isolated gap specific to the personal item alone.

Yes, as long as it's small enough to fit fully under the seat in front of you and within whatever size an airline enforces. Delta explicitly lists a small backpack among its acceptable personal item types, and United's own guidance uses backpacks as a direct example of what counts.

The word doing the work in both cases is small. A standard daypack, built for hiking or commuting, is a very different size than what these airlines mean by a personal item, so the bag type isn't the deciding factor, the actual dimensions are.

This is also where fare type matters. On a fare that includes both a carry-on and a personal item, the distinction barely matters in practice, since anything that doesn't fit as a personal item can usually just travel as your carry-on instead. The real risk shows up specifically on personal-item-only fares.

Most everyday travel backpacks run somewhere around 18 to 22 inches tall, which clears several airlines' carry-on limit but exceeds every published personal item limit on this list. If your backpack is in that range, it's using your carry-on allowance, not a free additional item.

That distinction matters most on a fare that only includes a personal item, like United's domestic Basic Economy. Bring a backpack that's actually carry-on sized on one of those fares, and you're either checking it for a fee or gate-checking it, not carrying it on for free.

A rough visual test that holds up reasonably well: if a bag needs both hands to carry comfortably when full, or if it clearly wouldn't slide flat under an economy seat without being tilted or squeezed, it's probably sized as a carry-on, not a personal item, regardless of what the manufacturer's listing calls it.

Across every published number in this comparison, the tightest common denominator is roughly 16 x 12 x 6 inches, Air France's limit. Pack to that size, or close to it, and you've all but guaranteed the bag clears anywhere from American's 18 x 14 x 8 down through the smaller European limits.

If your current bag is closer to 18 x 14 x 8, it'll still clear most U.S. carriers fine, just don't assume it automatically works as a personal item on Air France or similarly sized European carriers. Run the actual bag through the fit checker for your specific airline before you rely on it.

None of this replaces checking your specific airline, since packing to the smallest common number is a hedge, not a guarantee, particularly against airlines like Delta, Alaska, and Southwest that don't publish a number to check against in the first place, only a fit-under-the-seat expectation applied at the gate.