How do I choose the best travel backpack for a long trip?

For a long trip, I’d choose the backpack in this order: fit → size → carry comfort → access → durability → features. A great-looking bag that hurts after 20 minutes is still a bad travel backpack.

1. Pick the capacity

For most one-bag trips, 35–45L is the sweet spot. It gives you enough room for clothing, toiletries, electronics, and a few extras while remaining reasonably carry-on friendly.

• 30–35L: minimalist packing, warm climates, frequent laundry
• 35–40L: excellent general-purpose choice
• 40–45L: better for longer trips, colder weather, or bulkier clothing
• 50L+: consider this if you're checking luggage or carrying specialized gear

Don't choose capacity based purely on trip length. A two-month trip with weekly laundry can require less space than a one-week winter trip.

2. Check airline dimensions before liters

A "40L" label doesn't guarantee carry-on compliance. Airlines care about the backpack's external dimensions, and limits vary. REI notes that many airlines use limits around 45 linear inches, but you should check the specific airline you're flying.

If you're committed to carry-on-only travel, I'd generally target 35–40L and verify the packed dimensions.

3. Get the fit right

This is arguably the most important part.

Backpacks are sized according to torso length, not overall height. The hip belt should sit around your hip bones and transfer most of the load away from your shoulders.

When trying one on, load it with roughly the amount you'll actually carry and walk around for 10–15 minutes. Check for:

• No painful pressure points
• Shoulder straps sitting comfortably without large gaps
• Hip belt securely supporting the load
• Adjustable torso/back length
• Sternum strap that doesn't feel restrictive

4. Prefer a suitcase-style opening

For airports, hostels, hotels and frequent moving, I strongly prefer a clamshell/front-loading backpack over a traditional hiking top-loader. It opens broadly so you can see and access your belongings without digging through the entire bag.

Packing cubes work particularly well with this design.

5. Don't overlook the backpack's own weight

Two bags with the same capacity can feel very different because one may weigh substantially more before you've put anything in it. Since airline weight limits can also matter, avoid unnecessarily elaborate hardware and padding unless you'll actually benefit from it.

For a long trip, I'd rather have a lighter 40L bag with an excellent suspension system than a 45L bag loaded with features I rarely use.

6. Choose features based on your travel style

Mostly cities and public transit: Look for clamshell access, comfortable hip belt, laptop compartment, lockable zippers, water-bottle access and a luggage pass-through.

Lots of hiking: Prioritize an actual supportive frame, adjustable torso, substantial hip belt and ventilation. A hiking-oriented pack may carry much better than a pure travel pack.

Business/digital nomad: Look for good laptop/tablet protection, organization for chargers, and easy airport access.

Hostels/backpacking: Durability, compact dimensions, comfortable suspension and easy access matter more than having dozens of tiny pockets.

7. Test your packing before committing

Put everything you expect to take into the bag before buying it if possible. Ideally, also walk several miles with the loaded pack.

One useful rule: if you have extra space, don't automatically fill it. Larger bags tend to encourage overpacking.

My default recommendation

If you told me nothing else about your trip, I'd start by looking at a 35–40L clamshell backpack with a real hip belt, a good frame, adjustable torso fit, relatively low empty weight, and dimensions that meet your airline's carry-on rules.

If you're carrying camping gear, winter clothing, camera equipment, or going somewhere without reliable laundry, I'd move toward 40–50L or a checked bag.

If you tell me trip length, destinations/climate, whether you're flying carry-on only, and your budget, I can narrow this down to the best backpack type—and specific models worth considering.

Choosing the best travel backpack for a long trip comes down to matching the bag's capacity, comfort, and features to your specific style of travel. Here is a step-by-step breakdown to help you find the right one:

1. Sizing and Capacity

• 30L to 40L: Ideal for minimalist packing, and this size typically qualifies as a carry-on on most airlines, saving you checked bag fees and lost luggage worries.
• 45L to 55L+: Best if you are packing for multiple climates, carrying heavy camera gear, or need extra space, but you will likely need to check it.
• Torso Fit: Look for adjustable harness systems or specific size options (S/M/L) rather than "one-size-fits-all" bags so the weight sits properly on your hips, not your shoulders.

2. Access and Organization

• Clamshell Opening: Choose a bag that zips open flat like a suitcase rather than a traditional top-loading hiking backpack. It makes packing and finding items much easier without unpacking everything.
• Minimal External Pockets: Too many loose straps and exterior pouches get snagged in overhead bins, airport conveyor belts, and bus storage.
• Padded Laptop Sleeve: Essential if you travel with tech; ensure it is accessible from the side or main compartment.

3. Durability and Comfort

• Material: Look for weather-resistant, high-denier fabrics like 500D or 1000D Cordura, or recycled nylon with a DWR (Durable Water Repellent) coating.
• Stowable Harness: A zippered flap or panel to hide the shoulder straps and hip belt transforms your backpack into a clean duffel for flights or train rides.
• Load Lifters and Hip Belts: For long walks between terminals or transit hubs, a supportive, padded hip belt is non-negotiable to transfer weight off your back.

Traveler Experiences

Travelers often stress the importance of trying the bag on fully loaded before committing.

I found that going with a 40L bag forced me to pack lighter, which made moving through train stations and cobblestone streets a breeze.

Make sure the hip belt actually transfers weight to your hips rather than just wrapping around your waist, or your shoulders will hate you by day three.

If you'd like, let me know:

• How long your trip is and what kind of climate you're visiting
• Whether you plan to carry-on only or check a bag
• If you need a dedicated laptop compartment

I can recommend specific backpack models that fit your style.

Choosing the best travel backpack for a long trip comes down to finding the sweet spot between capacity, comfort , and airline compliance . Because you'll be carrying your life on your back for weeks or months, a standard school backpack won't cut it.

Here is a step-by-step framework to help you choose the right one:

1. Determine the Right Capacity (Size)

• 30L – 40L (The Sweet Spot): Ideal for long-term travel if you plan to pack light and do laundry weekly. This size almost always fits as a carry-on, saving you baggage fees and the risk of lost luggage.
• 40L – 50L (Max Carry-On): The absolute limit for overhead bins on most major airlines. Great if you need slightly more gear, but you’ll have to be mindful of strict budget airline weight limits.
• 55L+ (Checked Baggage): Usually too large for carry-on. Recommended only if you are carrying specialized gear, camping equipment, or traveling to extreme climates with bulky layers.

2. Prioritize Access: Clamshell vs. Top-Loading

• Clamshell Opening (Front-Loading): Zips open completely like a suitcase. This is a must-have for long trips because you can see and access everything instantly without unpacking your entire bag.
• Top-Loading: Traditional backpack style. Hard to keep organized, and finding an item at the bottom means unpacking everything. Best avoided unless you are doing backcountry hiking.

3. Check the Harness and Comfort System

• Stowable Straps: Look for a hip belt and shoulder straps that can zip away or tuck behind a flap. This prevents straps from getting snagged on airport baggage carousels or bus luggage compartments.
• Load Lifters & Padded Hip Belt: A good hip belt transfers 80% to 90% of the bag's weight onto your hips rather than your shoulders, which is a lifesaver during long walking commutes.

4. Durability and Weather Resistance

• Material: Look for high-denier fabrics like 500D or 1000D Cordura, or recycled nylon with a waterproof DWR coating or TPU lamination.
• Zippers: Ensure they are YKK zippers , preferably lockable for security in hostels and transit hubs.

If you'd like, let me know:

• Your approximate destination or climate
• Whether you plan to carry-on only

I can recommend specific backpack models that fit your exact trip style.

For a long trip, the best travel backpack is usually the one that balances comfort, airline compatibility, organization, and weight—not simply the one with the most liters.

1. Start with the size

For one-bag travel, 35–40L is the sweet spot for most people. Current travel-backpack testing consistently puts 40L-class packs near the practical maximum for carry-on travel.

• 28–32L: Minimalist traveler, frequent short trips.
• 35–40L: Best all-around choice for a long trip while staying carry-on friendly.
• 45L+: More comfortable for bulky clothing or lots of gear, but greater risk of exceeding airline limits.
• 50–70L: Better if you're checking the bag or doing genuine backpacking rather than one-bag travel.

Important: Check the actual dimensions for the airlines you'll use. A bag advertised as "carry-on" isn't necessarily compliant with every airline.

2. Prioritize the harness over clever pockets

You'll potentially carry this thing for hours through airports, train stations, and cities. Look for:

• Padded shoulder straps
• Adjustable torso length
• Hip belt that actually transfers weight to your hips
• Sternum strap
• Ventilated back panel
• Load-lifter straps on larger/heavier packs

For a long trip, I'd gladly sacrifice a few pockets for a significantly better suspension system. Testing of current 40L packs specifically highlights weight transfer and harness comfort as major differentiators.

3. Get a clamshell opening

For travel, I strongly prefer a backpack that opens like a suitcase rather than a traditional top-loading hiking pack.

A clamshell lets you:

• See nearly everything immediately
• Use packing cubes efficiently
• Access clothes at the bottom without unpacking
• Get through airport security more easily
• Keep your belongings organized during a multi-week trip

It's one of the features consistently recommended in current travel-pack testing.

4. Don't underestimate the backpack's empty weight

A 4.5-lb backpack versus a 2.5-lb backpack means 2 extra pounds before you've packed anything.

That's particularly important on international trips where some airlines impose weight limits on carry-ons. A slightly smaller, lighter backpack can therefore be more useful than a huge, feature-packed one.

As a rough target, I'd aim for around 3–3.5 lb or less for a 35–40L travel pack unless you specifically need a heavy-duty suspension system.

5. Think about what you'll actually carry

Before buying, make a rough pile of everything you'd take:

Clothes + toiletries + shoes + electronics + documents + miscellaneous gear.

Then ask:

"Could I comfortably live out of this for 7–10 days?" If yes, you can generally make a 35–40L backpack work for a much longer trip by doing laundry.

If you're traveling somewhere cold, carrying hiking equipment, camera equipment, or multiple pairs of shoes, you'll need substantially more space—or you'll need to accept checking a bag.

6. Choose organization based on your personality

There's no universally best layout.

If you like packing cubes: Choose a relatively open main compartment. You don't need 20 little pockets.

If you hate packing cubes: A bag with separate compartments and built-in organization may suit you better.

If carrying a laptop: Look for a padded, independently accessible laptop compartment.

If you're constantly moving: Prioritize simple access and compression over elaborate organization.

For example, the current

emphasizes carrying comfort and a backpacking-style harness, while the

is particularly appealing if organization is your priority. Both are in the size range I'd consider first for one-bag travel.

• Osprey Farpoint 40L - $200.00 (Nordstrom)
• Cotopaxi Allpa 35L - $230.00 (Nordstrom)
• Cotopaxi Allpa 42L - $255.00 (Nordstrom)
• Patagonia Black Hole MLC 45L - $167.30 (Backcountry)

7. My simple buying formula

For a long trip where you'll fly frequently, I'd look for:

35–40L + clamshell opening + good hip belt + adjustable harness + ≤3.5 lb empty + laptop compartment + stowable straps + durable/weather-resistant fabric.

Then try it fully loaded, not empty. Walk around for 10–15 minutes. If your shoulders, hips, or lower back are uncomfortable in the store, don't convince yourself you'll "get used to it."

My shortlist

• Best all-around: Osprey Farpoint 40 — excellent combination of capacity, carry comfort, and relatively low weight. Current 2026 testing also ranks it highly for value.
• Best for organization: Cotopaxi Allpa 35L — suitcase-like access and very structured organization.
• Best for maximum carry comfort: Tortuga Travel Backpack 40L — particularly appealing if you'll routinely carry a heavy load for long periods.
• Best if you're willing to check a bag: Move up into the 50–70L range and choose a true backpacking-style suspension system.

One final tip: Don't buy based on the number "40L" alone. Fit and external dimensions matter more than advertised capacity. A comfortable 35L backpack that you can carry and pack efficiently is usually better than a miserable 45L one.

If you tell me trip length, destinations/climate, whether you're flying carry-on only, and your budget, I can narrow this down to 3–5 specific backpacks worth considering.

If you're traveling somewhere cold, carrying hiking equipment, camera equipment, or multiple pairs of shoes, you'll need substantially more space—or you'll need to accept checking a bag.

6. Choose organization based on your personality

There's no universally best layout.

If you like packing cubes: Choose a relatively open main compartment. You don't need 20 little pockets.

If you hate packing cubes: A bag with separate compartments and built-in organization may suit you better.

If carrying a laptop: Look for a padded, independently accessible laptop compartment.

If you're constantly moving: Prioritize simple access and compression over elaborate organization.

• Osprey Farpoint 40L - $200.00 (Nordstrom)
• Cotopaxi Allpa 35L - $230.00 (Nordstrom)
• Cotopaxi Allpa 42L - $255.00 (Nordstrom)
• Patagonia Black Hole MLC 45L - $167.30 (Backcountry)

7. My simple buying formula

For a long trip where you'll fly frequently, I'd look for:

35–40L + clamshell opening + good hip belt + adjustable harness + ≤3.5 lb empty + laptop compartment + stowable straps + durable/weather-resistant fabric.

Then try it fully loaded, not empty. Walk around for 10–15 minutes. If your shoulders, hips, or lower back are uncomfortable in the store, don't convince yourself you'll "get used to it."

My shortlist

For a long trip, I’d choose a travel backpack by prioritizing fit and carry comfort first, airline dimensions second, and organization third. A 40L bag that feels good on your back is usually better than a 45L bag that you hate carrying.

1. Start with the size

For one-bag travel, 35–45L is the sweet spot:

• 30–35L: minimalist packing, warmer climates, frequent budget-airline travel.
• 35–40L: best all-around choice for most long trips.
• 40–45L: better for longer trips, colder climates, or bulkier gear.
• 45L+: increasingly difficult to keep within carry-on limits.

Don't rely on the liter number alone. Airlines enforce external dimensions, and a stuffed soft backpack can exceed its advertised dimensions.

2. Get a real suspension system

This is the biggest difference between a travel backpack and an oversized school backpack.

Look for:

• Padded shoulder straps
• A substantial hip belt
• Sternum strap
• Load lifters
• Adjustable torso/back length if possible
• A reasonably ventilated back panel

If you'll be carrying 15–20+ lb through airports, train stations and cities, a good hip belt can make a huge difference.

Try it loaded before buying. Put roughly the weight you'll actually travel with inside and walk around for 10–15 minutes.

3. Choose a clamshell opening

For long trips, I strongly prefer a backpack that opens like a suitcase rather than a traditional top-loader.

You can:

• Lay it flat on a hotel bed
• Use packing cubes efficiently
• Reach the bottom without unpacking everything
• Get through security more easily

This is particularly useful when you're moving hotels every few days.

4. Don't overvalue pockets

You want useful organization, not 25 tiny compartments.

I'd look for:

• Large main compartment
• Separate laptop/tablet compartment if needed
• Quick-access passport/phone pocket
• Water-bottle access
• Small internal organization for cables/chargers
• Compression straps

Packing cubes can provide the organization that the backpack itself lacks.

5. Consider how you'll actually travel

Mostly cities + lots of walking:
Prioritize a supportive harness and moderate weight.

Digital nomad/work travel:
Get excellent laptop protection and easy tech access.

Hostels/backpacking:
Prioritize comfort, durability and ventilation over sleek looks.

Frequent flights:
Keep it around 35–40L and verify every airline's dimensions.

Cold-weather travel:
40–45L makes more sense because jackets and shoes consume enormous amounts of space.

A few excellent starting points

Osprey Farpoint 40 Travel Pack

$184.95

Patagonia Black Hole MLC 45L

$249.00

Peak Design Travel Backpack 45L

$299.95

Cotopaxi Allpa 42L

$255.00

• Osprey Farpoint 40: My default recommendation for someone who will walk a lot with the bag. It combines a relatively compact 40L format with a genuine load-bearing harness. Current reviews continue to rate it highly for carry comfort and value.
• Patagonia Black Hole MLC 45L: Better if you think of your backpack primarily as luggage that can be carried on your back. It's a 45L convertible design and particularly appealing if durability/weather resistance matter.
• Peak Design Travel Backpack 45L: Excellent for tech-heavy or camera-heavy travel, with an expandable 35–45L design.
• Cotopaxi Allpa 42L: Good if organization and suitcase-style packing are your priorities.

My rule of thumb

If I were buying one bag for a multi-week international trip, I'd aim for:

35–40L + clamshell opening + good hip belt + under ~3.5 lb empty + dimensions that meet the airlines you'll actually fly.

And I'd rather pack less into a comfortable 40L than buy a huge 50–60L pack and end up carrying unnecessary stuff.

If you tell me your trip length, destinations/climate, whether you'll check the bag, your budget, and whether you're bringing a laptop/camera, I can narrow this down to 3 specific backpacks.

Choosing the best travel backpack for a long trip comes down to finding the sweet spot between comfort, durability , and airline compliance . Here is a step-by-step breakdown to help you choose the right one:

• Size and Capacity: Look for a 35L to 45L bag for long-term travel. This size is generally small enough to pass as carry-on luggage on most airlines (saving you baggage fees and lost-baggage stress) yet large enough to hold a capsule wardrobe for months.
• Access Type (Clamshell vs. Top-Loading): Choose a clamshell opening (zips open completely like a suitcase) instead of a top-loading hiking backpack. It makes packing, organizing, and finding your gear infinitely easier without unpacking everything.
• Harness System and Comfort: Look for a padded, adjustable hip belt and load-lifter straps. For long trips, transferring 70% of the weight to your hips rather than your shoulders is a game-changer when walking through transit hubs.
• Durability and Materials: Check for water-resistant, high-denier fabrics like 500D or 1000D Cordura, or reinforced ballistic nylon. Heavy-duty YKK zippers are also a must-have for a bag that will take a beating.
• Security and Pockets: Look for lockable zipper loops, a hidden passport pocket, and a dedicated padded sleeve if you are traveling with a laptop or tablet.

If you'd like, let me know:

• Your approximate trip duration and destination climate (hot vs. cold gear)
• Whether you plan to carry-on only or check a bag
• Your budget

I can recommend specific backpack models that fit your exact travel style.

Choosing the best travel backpack for a long trip comes down to finding the sweet spot between comfort, capacity , and airline compliance.

Here is a step-by-step framework to help you choose the right one:

1. Size and Capacity
   • 30L to 40L: Ideal for carry-on only travel. It forces you to pack light and fits in almost all overhead bins.
   • 45L to 55L+: Gives you more room, but you may have to check it on smaller budget airlines, which risks lost luggage.
2. Loading Style (Clamshell vs. Top-Loading)
   • Clamshell opening: Zips open flat like a suitcase. This is a must-have for long-term travel because you can see and access everything instantly without unpacking the whole bag.
   • Top-loading: Traditional hiking style. Harder to find items at the bottom, but usually offers better load-bearing frames for heavy hiking.
3. Fit and Comfort
   • Torso length matters: Look for a pack with an adjustable torso length or one that comes in specific sizing (S/M/L) rather than "one size fits all."
   • Hip belt and load lifters: A padded hip belt transfers 80% of the bag's weight off your shoulders and onto your hips, which is crucial for walking through transit hubs.
4. Durability and Weather Resistance
   • Material denier: Look for high-density nylon (like 500D or 1000D Cordura) or waterproof tarpaulin/ripstop fabrics.
   • Zippers: Ensure they are heavy-duty, self-healing YKK zippers that can handle being overstuffed.
5. Security and Organization
   • Lockable zippers: Look for zipper loops that accept TSA-approved luggage locks.
   • Hidden pockets: Useful for stashing a passport or emergency cash against your lower back.
   • Internal compression straps: Keep your clothes from shifting around and sliding to one side.

If you'd like, let me know:

• How long your trip is and what kind of climate/destinations you're visiting
• Whether you plan to carry-on only or don't mind checking a bag

I can recommend specific backpack models that fit your exact travel style.

For a long trip, the best travel backpack is usually the smallest one that comfortably holds what you need. A good starting point is around 35–40L if you want to travel carry-on-only; larger packs make sense if you’ll carry bulky cold-weather gear, camping equipment, or go a long time without laundry.

What to prioritize

1. Fit and comfort — most important

   • Choose based on torso length, not height.
   • Look for padded, adjustable shoulder straps, a supportive hip belt, and a sternum strap.
   • When loaded, most of the weight should sit on your hips rather than your shoulders.
   • Ideally, try it with 15–25 lb (7–11 kg) inside before buying. An empty backpack can feel great but become miserable when loaded.

2. Capacity

   Trip style	Approx. size
   Very minimalist	25–30L
   One-bag travel	30–40L
   More clothes/gear	40–45L
   Camping/cold weather	50L+

   For most long international trips involving regular laundry, I'd lean toward 35–40L rather than 50–60L.

3. Clamshell/panel opening

   A backpack that opens like a suitcase is much easier to pack and unpack than a traditional top-loader. This is particularly valuable when you're moving hotels every few days.

4. Airline compatibility

   Don't assume "carry-on" means it works on every airline. Check the actual dimensions against the airlines you'll use, especially if you'll fly budget carriers.

5. Organization

   Useful features include:

   • Large main compartment
   • Separate laptop/tablet compartment if needed
   • Easy-access passport/phone pocket
   • Water-bottle pocket
   • Compression straps
   • Lockable or secure zippers
   • Stowable shoulder straps for checked luggage

   Don't overvalue having dozens of tiny pockets—you can get similar organization with packing cubes.

6. Weight and durability

   An ultralight bag isn't automatically better. A slightly heavier bag with a substantially better harness can be much more comfortable. Conversely, avoid unnecessarily heavy bags when you're going to carry them for hours.

The test I'd use

Before buying, load it as you would for your actual trip and walk around for 20–30 minutes. Check:

• Does the hip belt stay comfortably on your hip bones?
• Do the shoulder straps avoid digging into your neck?
• Is anything poking your back?
• Can you reach your essentials without unpacking everything?
• Can you lift it into an overhead bin comfortably?
• Does it feel stable when you walk quickly or climb stairs?

REI's fitting guidance similarly emphasizes torso length, hip fit, and testing the pack with weight rather than relying on empty-pack comfort.

A useful rule of thumb

If your trip is mostly cities, trains, planes, hotels/hostels, and occasional walking, I'd prioritize:

35–40L + clamshell opening + excellent harness + carry-on dimensions + relatively low weight.

If you're going to be hiking extensively or carrying camping gear, choose a real internal-frame backpacking pack instead; those are designed to transfer heavier loads to your hips.

If you tell me trip length, destinations/climate, whether you want carry-on only, and your budget, I can narrow this down to the right size and type—and specific backpacks if you want to shop for one.

Choosing the best travel backpack for a long trip comes down to balancing comfort, capacity, and airline compliance . For a long journey, the "best" bag isn't the one with the most pockets—it’s the one you can comfortably haul through a chaotic train station, run to catch a flight with, and easily live out of for months.

1. Dial in the Right Size (Capacity)

• 30L – 35L (The Minimalist Sweet Spot): Ideal if you plan to pack light, embrace doing sink laundry every few days, and want a bag that easily slips into overhead bins or under seats.
• 40L – 45L (The Maximum Carry-On): Widely considered the golden zone for long-term travel. It gives you enough room for varying climates or an extra pair of shoes without crossing into checked-bag territory on most airlines.
• 50L+ (The Heavy Hauler): Only recommended if you are carrying specialized gear, cold-weather/four-season clothing kits, or camping setups. Be warned: these get heavy fast and will force you to check your bag.

2. Prioritize Access and Organization

• Clamshell vs. Top-Loading: Skip traditional top-loading hiking backpacks. Look for a clamshell/panel-opening design (it unzips like a suitcase) so you can see and access all your gear instantly without unpacking everything.
• Minimal Internal Pockets: Built-in organizer panels can eat into your usable volume. A wide-open main compartment paired with separate packing cubes gives you modular control over your space.
• External Access: A dedicated, easily accessible padded compartment for a laptop or tablet is vital if you work on the road or need quick security checks at airports.

3. Comfort and Harness System

• Torso Fit and Hip Belts: If you plan on walking more than a few blocks with your pack fully loaded, a proper hip belt that transfers weight to your hips (rather than leaving 100% of the strain on your shoulders) is a game-changer.
• Stowable Straps: For travel, look for a harness system that zips away or stows behind a flap. This keeps straps from snagging on conveyor belts, bus cargo holds, or overhead bins when checking or gate-checking your bag.

Real Traveler Experiences

“For me, it's weight, durability, and ability to (mostly) pass for a personal item.”

Popular, road-tested options frequently recommended by long-term travelers include the [Osprey Farpoint 40 Go to product viewer dialog for this item. ](https://www.packhacker.com/guide/best-travel-backpack/) (budget-friendly and excellent weight distribution), the Cotopaxi Allpa 35L Go to product viewer dialog for this item. (loved for its internal compartmentalization), and the Aer Travel Pack Go to product viewer dialog for this item. series for sleek, durable urban travel.

To help narrow down the exact model or size you need, tell me:

• What climates or regions are you visiting?
• Will you be carrying a laptop or heavy tech?
• Do you prefer to stick strictly to carry-on size limits?

For a long trip, I’d choose a travel backpack based on how you travel, not simply how many liters it holds.

1. Start with capacity

A useful rule of thumb:

• 30–35 L: Best for minimalist one-bag travel, especially if you can do laundry regularly.
• 35–40 L: The sweet spot for many travelers—enough for roughly a week or more with efficient packing while remaining relatively carry-on friendly.
• 40–45 L: Better if you need more clothing, bulky gear, or don't want to pack quite as tightly.
• 50+ L: Consider this mainly if you're carrying specialized equipment or don't intend to travel carry-on-only.

REI's current travel-pack guidance puts 30–40 L toward carry-on use and 40–55 L toward longer trips, while emphasizing that airline dimensions—not just liter capacity—determine whether a bag qualifies as carry-on.

2. Prioritize fit over features

This is probably the most important consideration if you'll be carrying the bag for hours.

Look for:

• Padded, adjustable shoulder straps
• A real hip belt if you're carrying substantial weight
• A sternum strap
• An internal frame or other load-support system
• Adjustable torso length, if available
• Good ventilation

Your torso length matters more than your overall height when sizing a backpack. Ideally, load the backpack with representative weight and walk around in it before buying.

3. Decide whether you want a "travel" or "hiking" backpack

For airports, trains and cities, I'd favor a travel backpack with:

• Suitcase-style opening
• Laptop compartment
• Multiple organization pockets
• Stowable straps
• Lockable zippers
• Easily accessible top/front pockets

If your trip involves lots of actual hiking, a hiking-oriented pack with better suspension and ventilation may be considerably more comfortable.

4. Don't underestimate the backpack's empty weight

A 45-L bag that weighs 4 lb gives you substantially less useful payload than a 35-L bag that weighs 2 lb if you're trying to keep your total luggage light.

The temptation is to buy the biggest bag available. In practice, a smaller bag can force you to pack less, which often makes long-term travel easier.

5. Think about access

For long trips, I'd strongly prefer a backpack that opens like a suitcase rather than one where you have to dig down from the top.

You'll appreciate this enormously when you're staying in a different place every few days.

6. A few good starting points

Osprey Farpoint 40 Travel Pack

$159.95

Cotopaxi Allpa 35L Travel Pack

$230.00

Peak Design Travel Pack 30L

$299.95

Aer Travel Pack 4 X-Pac 35L

$289.00

• Osprey Farpoint 40 — my pick if carrying comfort is your priority. It combines a backpacking-style suspension with travel-oriented organization.
• Cotopaxi Allpa 35L — excellent if you want simple suitcase-style packing and organization. REI currently lists it among its top carry-on travel packs.
• Peak Design Travel Pack 30L — particularly attractive if you carry camera/computer gear.
• Aer Travel Pack 4 35L — a good choice if you want a sleek, structured urban/business-travel bag.

My general recommendation

For an extended international trip where you'll be moving around frequently, I'd aim for 35–40 L, keep the fully loaded weight around 15–20 lb if possible, and choose the bag that feels best on your back rather than the one with the most pockets.

And check the specific airlines you'll be flying before buying—carry-on limits vary, and some airlines/aircraft are substantially more restrictive.

If you tell me trip length, destinations/climate, whether you'll hike, your budget, and whether you want carry-on-only, I can narrow this down to 3–5 backpacks that fit your trip.