Travel Backpacks: Carry-On Backpacks for One-Bag Travel

One of our strongest picks is the Cotopaxi Allpa 35L Travel Pack, a standout in our Best Travel Backpacks for Backpacking Europe list. The Osprey Farpoint 40 is another excellent choice.

Start with your main use and budget, then compare our shortlists: Best Travel Backpacks for Backpacking Europe, Best Travel Backpacks for Carry-On Only Travel, Best Travel Backpacks for Digital Nomads.

35 to 45 liters suits one-bag travel. Check your airlines' carry-on dimensions.

35 to 40 liters is the range most multi-country Europe backpackers settle on. It's large enough for several weeks of clothing rotated through hostel laundry, and small enough to still qualify as a carry-on or small personal item on the budget airlines (Ryanair, Wizz Air, easyJet) common for intra-Europe travel.

Yes, more strictly than most US carriers. Ryanair's free personal item allowance is roughly 40 x 20 x 25 centimeters, smaller than most travel backpacks even at 35L. Budget carriers routinely measure bags at the gate and charge a fee on the spot for oversized ones, so check the specific carrier's limit rather than assuming a 'carry-on sized' bag will pass for free.

Suitcase-style openings generally work better for hostel stays, since laying the bag open on a bunk to find items is easier than digging top-down in a shared, often dim room. A top-loading bag can also be harder to repack quietly early in the morning without waking roommates, since accessing the bottom means unpacking from the top.

Most US carriers allow a carry-on up to roughly 22 x 14 x 9 inches, and most international carriers are stricter, often closer to 21.5 x 13.5 x 7.5 inches or a 40-liter volume cap. A 35 to 40-liter backpack that measures under 22 x 14 x 9 inches clears nearly every US carrier. For airlines with tighter international limits (Ryanair, easyJet, and similar budget carriers), check the exact bag before flying, since several 40 to 45-liter packs technically exceed those smaller sizers even though they pass on US domestic carriers.

Not for US domestic carriers, where 40 liters is a standard carry-on size and packs like the Osprey Farpoint 40 are built specifically to that limit. For budget European carriers with an 8 to 10-kilogram or 40 x 20 x 25-centimeter personal item limit, a 40-liter pack can be too large and may need to be gate-checked or paid for as a larger cabin bag. Confirm the airline's specific limit before a trip that includes a budget carrier leg.