Carry-on backpack size
A backpack can be your carry-on if it fits the airline limit, usually 22 × 14 × 9 in (56 × 36 × 23 cm). That is roughly a 40 to 45 liter travel pack. Smaller backpacks can go under the seat as a personal item.
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Airlines that accept this bag
Airlines that won’t accept it
* guideline, not published
Carry-on limits for backpacks
| Airline | Carry-on | Weight |
|---|---|---|
| American Airlines | 22 × 14 × 9 in55.9 × 35.6 × 22.9 cm | No published weight limit |
| Delta Air Lines | 22 × 14 × 9 in55.9 × 35.6 × 22.9 cm | No published weight limit |
| United Airlines | 22 × 14 × 9 in55.9 × 35.6 × 22.9 cm | No published weight limit |
| Southwest Airlines | 24 × 16 × 10 in61 × 40.6 × 25.4 cm | No published weight limit |
| JetBlue | 22 × 14 × 9 in55.9 × 35.6 × 22.9 cm | No published weight limit |
| Alaska Airlines | 22 × 14 × 9 in55.9 × 35.6 × 22.9 cm | No published weight limit |
| Frontier Airlines | 24 × 16 × 10 in61 × 40.6 × 25.4 cm | 35 lb |
| Ryanair | 21.7 × 15.7 × 7.9 in55 × 40 × 20 cm | 22 lb |
| easyJet | 22 × 17.7 × 9.8 in56 × 45 × 25 cm | 33.1 lb |
| British Airways | 22 × 17.7 × 9.8 in56 × 45 × 25 cm | 50.7 lb |
| Lufthansa | 21.7 × 15.7 × 9.1 in55 × 40 × 23 cm | 17.6 lb |
| Emirates | 21.7 × 15 × 8.7 in55 × 38 × 22 cm | 15.4 lb |
| Qantas | 22 × 14.2 × 9.1 in56 × 36 × 23 cm | 15.4 lb |
Largest carry-on backpack
Most 40 liter travel backpacks measure about 21 × 13 × 9 in and fit US airline limits. A 45 liter pack is usually at the limit. For European airlines with 55 × 40 × 20 cm limits, look for a pack no deeper than 20 cm.
Soft bags grow
A soft backpack gets deeper when packed. Measure it full, not empty, and use compression straps to stay inside the sizer.
Frequently asked questions
What size backpack can be a carry-on?
Up to 22 × 14 × 9 in (56 × 36 × 23 cm) on most US airlines, and 55 × 40 × 20 cm on many international airlines.
Is a 40L backpack carry-on size?
Usually yes. Most 40 liter travel packs fit within 22 × 14 × 9 in when not overstuffed.
Can I bring a backpack and a carry-on?
Yes on most full-service airlines, if the backpack is small enough to count as your personal item.