Usually, you can’t carry on a 40l backpack because it exceeds the standard size limits for most airlines. You’ll likely need to check it unless your bag is soft-sided and not fully packed. Measure your bag carefully before heading to the airport to avoid surprise fees.
Can you carry your 40l backpack
Most airlines set strict limits on the dimensions of bags brought into the cabin. A 40l backpack is often wider and deeper than these limits, even if it feels compact when empty.
| Airline Situation | Likely Outcome | Reason |
|---|---|---|
| Budget airline flight | Must check | Strict 55x40x20cm limits apply |
| Full-service airline | Maybe | Depends on specific cabin dimensions |
| Soft-sided, underfilled bag | Possible | It can squeeze into the sizer |
| Rigid frame backpack | Must check | It can’t compress to fit |
| International long-haul | Maybe | Larger overhead bins are common |
| Regional small plane | Must check | Very small overhead bin space |
Factors that decide if your bag fits
The main factor deciding if your bag counts as a carry-on is its physical dimensions when fully loaded, rather than its volume in liters. Airlines use metal sizers at the gate to verify if a bag will fit into the overhead bin or under the seat. If your bag exceeds the maximum length, width, or depth allowed by the Transportation Security Administration, it must go into the cargo hold.
Rigid frames or thick padding prevent a bag from being compressed. If you have a soft-sided pack, you might be able to remove bulky items or cinch the straps to reach the required size. If your bag is rigid, then you must check it; if it’s soft-sided, you can try to compress it to fit the sizer.
How to travel with a larger bag
If you decide to bring your 40l pack, follow these steps to manage the process:
- Measure your bag empty and full. Use a tape measure to check the height, width, and depth to see if they stay under the airline’s maximum limit.
- Remove external attachments. Take off any hanging gear, loose straps, or external pockets that add unnecessary bulk to the frame.
- Use compression straps. Pull the side straps tight to shrink the profile of the bag so it fits easily into the overhead bin.
- Prepare for gate checking. Have a plan to remove your laptop and fragile items if a gate agent forces you to check the bag at the last minute.
The common packing mistake
The biggest mistake is assuming that volume equals dimensions. Travelers often think that because a bag is labeled “40l,” it will automatically fit the “carry-on” category. This leads to unexpected baggage fees at the gate when the bag fails to slide into the metal sizer.
You can avoid this by ignoring the liter rating and checking the actual exterior measurements against the airline’s website before you pack. Measuring the bag while it’s fully loaded is the only way to know if it will pass the test.
When to stop and get help
You should stop trying to force your bag into the cabin if you notice these signs:
- The bag frame is rigid and clearly exceeds the airline’s maximum height limit.
- The weight of your gear exceeds the airline’s carry-on limit, usually 7 to 10 kilograms.
- A gate agent requests that you place the item in the sizer and it gets stuck.
If these occur, check the bag at the counter to avoid higher fees at the gate.
Frequently asked questions
Can I carry on a 40l backpack on domestic flights?
Usually no, because most domestic airlines limit carry-ons to 22x14x9 inches. A 40l pack often exceeds these specific dimensions when filled to capacity, which forces you to check it at the gate.
Is it safe to check a 40l backpack?
Yes, it’s generally safe if you use a protective travel cover. These covers prevent loose straps from catching on conveyor belts and protect the fabric from tears during the luggage handling process.
How much does it cost to check my bag?
It varies by airline and ticket class, often costing significantly less than the price of a checked bag. Check your specific airline’s website under “baggage fees” to find the exact price for your flight.
Does the weight of my bag matter?
Yes, most airlines set a maximum weight limit between 7 and 10 kilograms for carry-on items. Even if your 40l bag fits the size requirements, it will be checked if it’s too heavy.
What happens if my bag is too big?
You’ll be required to check the bag into the cargo hold. This often results in a higher fee at the gate compared to paying for a checked bag during your initial online booking.
Can I bring a smaller personal item too?
Yes, most airlines allow one personal item like a small purse or laptop bag in addition to your main carry-on. Ensure your personal item fits under the seat in front of you.
Conclusion
Check the airline’s official website for their exact size limits before you start packing your bag. If your gear fits within these dimensions, you can proceed to the gate, but be ready to check it if the flight is full. If the bag doesn’t fit the sizer, go to the check-in counter immediately.