Compare 12 US airlines
Personal item size by airline
Under-seat bag dimensions in inches and centimeters when the airline publishes them. If there is no L×W×H, we say under seat / not published — we do not copy another carrier’s inches.
Figures from airline pages as of 2026-09-10 — confirm before you fly
| Airline | Size (in) | Size (cm) | Page |
|---|---|---|---|
| American Airlines | 18 × 14 × 8 in | 45 × 35 × 20 cm | View American personal item |
| Delta Air Lines | Under seat / not published | Under seat / not published | View Delta personal item |
| United Airlines | 9 × 10 × 17 in | 22 × 25 × 43 cm | View United personal item |
| Southwest Airlines | Under seat / not published | Under seat / not published | View Southwest personal item |
| Alaska Airlines | Under seat / not published | Under seat / not published | View Alaska personal item |
| JetBlue Airways | 17 × 13 × 8 in | 43.2 × 33 × 20.32 cm | View JetBlue personal item |
| Frontier Airlines | 18 × 14 × 8 in | CoC: 20 × 35 × 45 cm | View Frontier personal item |
| Allegiant Air | 8 × 14 × 18 in | 20 × 35 × 45 cm | View Allegiant personal item |
| Hawaiian Airlines | Under seat / not published | Under seat / not published | View Hawaiian personal item |
| Sun Country Airlines | 17 × 13 × 9 in | ~43 × 33 × 23 cm (converted) | View Sun Country personal item |
| Avelo Airlines | 17 × 13 × 9 in | 43 × 33 × 22 cm | View Avelo personal item |
| Breeze Airways | 17 × 13 × 8 in | ~43 × 33 × 20 cm (converted) | View Breeze personal item |
American Airlines
- Size (in)
- 18 × 14 × 8 in
- Size (cm)
- 45 × 35 × 20 cm
Delta Air Lines
- Size (in)
- Under seat / not published
- Size (cm)
- Under seat / not published
United Airlines
- Size (in)
- 9 × 10 × 17 in
- Size (cm)
- 22 × 25 × 43 cm
Southwest Airlines
- Size (in)
- Under seat / not published
- Size (cm)
- Under seat / not published
Alaska Airlines
- Size (in)
- Under seat / not published
- Size (cm)
- Under seat / not published
JetBlue Airways
- Size (in)
- 17 × 13 × 8 in
- Size (cm)
- 43.2 × 33 × 20.32 cm
Frontier Airlines
- Size (in)
- 18 × 14 × 8 in
- Size (cm)
- CoC: 20 × 35 × 45 cm
Allegiant Air
- Size (in)
- 8 × 14 × 18 in
- Size (cm)
- 20 × 35 × 45 cm
Hawaiian Airlines
- Size (in)
- Under seat / not published
- Size (cm)
- Under seat / not published
Sun Country Airlines
- Size (in)
- 17 × 13 × 9 in
- Size (cm)
- ~43 × 33 × 23 cm (converted)
Avelo Airlines
- Size (in)
- 17 × 13 × 9 in
- Size (cm)
- 43 × 33 × 22 cm
Breeze Airways
- Size (in)
- 17 × 13 × 8 in
- Size (cm)
- ~43 × 33 × 20 cm (converted)
Airline pages
- American Airlines Personal item
- Delta Air Lines Personal item
- United Airlines Personal item
- Southwest Airlines Personal item
- Alaska Airlines Personal item
- JetBlue Airways Personal item
- Frontier Airlines Personal item
- Allegiant Air Personal item
- Hawaiian Airlines Personal item
- Sun Country Airlines Personal item
- Avelo Airlines Personal item
- Breeze Airways Personal item
FAQ
- What is a personal item?
- The under-seat bag that travels in addition to (or instead of) a full-size carry-on. Size rules are per airline — some publish L×W×H, others only say it must fit under the seat.
- Which airlines don’t publish personal item dimensions?
- Delta Air Lines, Southwest Airlines, Alaska Airlines, and Hawaiian Airlines publish under-seat fit without L×W×H. Do not copy inches from United or Frontier onto those carriers.
- Is a personal item free?
- On every airline in this set, a size-compliant personal item is published as free on typical fares. An oversized “personal item” can be reclassified as a carry-on or checked bag.
- What’s a typical published personal item size?
- Published examples in this set include American 18 × 14 × 8 in; United 9 × 10 × 17 in; JetBlue 17 × 13 × 8 in. Use the table for the full list — axis order is the airline’s, not a normalized 22×14×9.
- What if my bag doesn’t fit under the seat?
- It may count as your carry-on or need to be checked. Gate fees are airline-specific — we only list dollars that appear on that airline’s own page.
Disclaimer
Bag rules change. Confirm size, fee, and fare rules on the airline site before you travel. BagRule is a publisher site and does not sell tickets or bags.