Personal Item Size: What Actually Counts

A personal item is the second, smaller bag airlines let you bring in addition to your main carry-on, meant to fit under the seat in front of you rather than the overhead bin. Purses, small backpacks, laptop bags, and briefcases are the standard examples across nearly every airline's official wording.

It's included free on almost every fare from almost every airline, Basic Economy included, which makes it the one bag most travelers can count on regardless of how cheap their ticket is. The catch is that 'fits under the seat' isn't a fixed measurement, and airlines that do publish a number don't all publish the same one.

No. TSA's own guidance on bag size is unambiguous: 'Size dimensions of carry-on baggage allowed in the cabin of the aircraft vary by airline. Contact your airline to ensure what can fit in the overhead bin or under the seat in front of you.' That covers the personal item as much as the carry-on. TSA screens the contents of your bag, not its dimensions, and it publishes no personal item size rule of its own.

So when a search result promises 'the TSA personal item size,' what it's actually describing is one airline's policy, dressed up as a universal government rule. There isn't one.

American Airlines and Allegiant both publish 18 x 14 x 8 inches, the largest official personal item allowance among the carriers that state a number. Frontier matches that same 18 x 14 x 8 inch size and additionally caps it at 35 lb, the only carrier in this group with a published personal item weight limit.

United publishes 17 x 10 x 9 inches, notably narrower than American's on width. JetBlue and Sun Country both list 17 x 13 x 8 and 17 x 13 x 9 inches respectively, and Avelo publishes 17 x 13 x 9 inches as well.

Air Canada states 17 x 13 x 6 inches, and Air France and British Airways both use an identical 16 x 12 x 6 inches, the smallest allowance among carriers with a published number. Air France's personal item shares its combined weight cap with the carry-on rather than having its own separate figure, 12 kg (26 lb) total in Economy. Turkish Airlines and Lufthansa both publish 15.75 x 11.81 x 5.91 inches (40 x 30 x 15 cm), with Turkish additionally capping it at 4 kg (8.8 lb). Ryanair publishes 15.75 x 11.81 x 7.87 inches for its free personal item, close to the Turkish and Lufthansa figure but noticeably deeper.

Notice how much this range actually spans: from 15.75 x 11.81 x 5.91 inches at the small end to 18 x 14 x 8 inches at the large end. A bag built to the larger figure can be nearly twice the usable volume of one built to the smaller figure, even though both are described the same way, as a free 'personal item.'

Because the personal item is free on nearly every fare, including Basic Economy, a lot of travelers treat it as an afterthought and pack their carry-on carefully while stuffing the personal item with whatever's left over. That's backwards on any airline with a real size check at the gate, since an oversized 'personal item' that's actually a second carry-on in disguise is one of the more common reasons people get stopped at boarding.

It's also the bag most worth buying deliberately if you fly a mix of airlines. A personal item sized to the smallest published figure will clear every airline in this list, while one sized to the largest, American or Allegiant's 18 x 14 x 8 inches, may not pass under the seat on a carrier using the tighter 16 x 12 x 6 inch rule.

Delta, Alaska, Hawaiian, Southwest, and Qatar Airways all allow a free personal item, but none of them publish official dimensions for it. Their language is consistently qualitative: it needs to fit under the seat in front of you, without a stated length, width, or height.

If you see a specific personal item size quoted for Delta, Alaska, Hawaiian, or Southwest anywhere online, that number is a third-party estimate, not an airline policy. Treat it as a rough guideline at best, and if your bag is borderline, size it to fit comfortably under an average economy seat rather than to a number that isn't actually official.

Emirates is the exception worth knowing before you fly. Its Economy and Premium Economy cabins get exactly one cabin bag, 7 kg in Economy, 10 kg in Premium Economy, with no separate free personal item on top of it. Business and First Class passengers do get a second piece, a briefcase or garment bag, but Emirates documents that as part of a two-piece cabin allowance rather than a personal item in the sense American or United use the term.

If you're used to flying a carrier that always includes a laptop bag on top of your carry-on, Emirates Economy is where that assumption breaks. Pack accordingly, since anything that doesn't fit in your single 7 kg allowance has to go in checked baggage.

If you want one bag that clears nearly every airline's personal item rule without checking each time, size it to the smallest published figure in this list, 16 x 12 x 6 inches, matching Air France and British Airways. A bag that size will also clear every larger allowance, including American and Allegiant's 18 x 14 x 8 inches.

For airlines that don't publish an official number, that same conservative size is still your safest bet, since it's smaller than every stated allowance from every carrier that does publish one. Before a specific trip, run your bag's real measured dimensions through the fit checker to confirm it against your actual airline rather than assuming the smallest-common-denominator size covers every edge case.