Personal item limits vary far more than carry-on limits do, and the gap between the tightest and the most generous is bigger than most travellers expect. Ranked by usable volume — the multiple of the three dimensions — smallest first.
| # | Airline | Limit | Volume | Bags that fit |
|---|---|---|---|---|
| 1 | United Airlines | 17 × 10 × 9 | 1,530 in³ | 12 of 25 |
| 2 | JetBlue | 17 × 13 × 8 | 1,768 in³ | 11 of 25 |
| 3 | Breeze Airways | 17 × 13 × 8 | 1,768 in³ | 11 of 25 |
| 4 | Sun Country Airlines | 17 × 13 × 9 | 1,989 in³ | 14 of 25 |
| 5 | American Airlines | 18 × 14 × 8 | 2,016 in³ | 15 of 25 |
| 6 | Frontier Airlines | 18 × 14 × 8 | 2,016 in³ | 15 of 25 |
| 7 | Allegiant Air | 18 × 14 × 8 | 2,016 in³ | 15 of 25 |
Delta, Southwest, Alaska, Hawaiian are absent from this ranking because they publish no personal item dimensions at all — the only requirement is that the bag fits under the seat. Ranking them against an invented number would be guesswork presented as fact, which is what most comparison charts do here.
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United Airlines, at 17 × 10 × 9 inches. Delta, Southwest, Alaska, Hawaiian publish no personal item dimensions at all, so they cannot be ranked.
Yes, without exception. Every US carrier includes one free under-seat personal item on every fare class, including Basic Economy and the cheapest ultra-low-cost fares. Only the overhead-bin carry-on ever costs extra.
Yes, on every US airline. They measure the outside of the bag, so wheels, handles, straps and external pockets all count. This is why a suitcase sold as a "20-inch carry-on" is often 22 inches overall.
Airlines revise baggage policy without announcement, usually alongside fare changes. Every figure here was checked against the carrier’s own published policy in August 2026 and each links to the source it came from.
Manufacturers publish dimensions inconsistently, and a “20-inch” spinner is almost never 20 inches once you count the wheels. Where a brand states dimensions including wheels and handles, that’s the number we use. Where it only publishes the case, we say so on the card. Airlines measure the outside of your bag — wheels, handles, straps and all. Anything marked borderline is down to the gate agent, and remember that a soft bag squashes into a sizer while a hard shell won’t.
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Limits verified August 2026 against each carrier’s published policy. Airlines change these without notice — always confirm before you fly. Spirit Airlines ceased operations on 2 May 2026 and is no longer listed.
Airline Bag Size Checker v1.0.15 · last updated 2026-08-12