What Size Backpack Do I Need For Travel?

Backpack and yoga mat.

Here at South East Asia Backpacker, we get asked a ton of questions about the best backpacks for travel. 

And the one that we’re asked over and over again…

“How big should my backpack be?”

While the in-depth answer is different for everybody, the simple answer is almost always “smaller than you think.”

Keep reading as we dive into the different sizes of backpacks and uncover which is most suitable for you! 

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Backpack Volume

Backpack volume is measured in litres and is touted as the most important factor to consider when purchasing a travel bag. 

But it doesn’t tell the whole story. 

The size, shape and materials of a given backpack will affect how much gear you can fit into and how easily you can pack the bag. 

For example, a 40-litre, triangular backpack will be tougher to organise than a rectangular shaped bag of the same volume. Likewise, a backpack made of a tough, rigid material won’t flex as you fill it to the brim. This can make packing and carrying a full load more challenging. 

A rectangular backpack made of flexible, yet robust materials like nylon will generally be the easiest to pack and carry. Backpack manufacturers know this and most produce a quality range of travel backpacks that fit the bill. 

But that still doesn’t answer the question — What size bag do I need for travel?

We surveyed our audience of travellers to see what size and brand of bags are most common among backpackers. 

The answers fit into four size brackets: 25-30 litres, 40-46 litres, 50-60 litres and more than 65 litres.  


Best for…

A 25-30-litre backpack is best for city breaks and long weekend trips if you pack light. Some very light packers can get away with travelling indefinitely with a bag of this size but they are in the minority. Most long term travellers require a larger bag than this. 

Some backpackers will use a 25-30-litre bag as a daypack because it’s big enough to carry everything you’ll need for a day out. Be aware though, unless you pick up a collapsible 25-30-litre bag, it can be difficult to carry along with your main bag. 

Dave Wears a Standard Luggage Daily Backpack
A daypack is a backpacker’s best friend!

Not ideal if…

A bag of this size isn’t suitable for heavy packers or those who like their creature comforts. If you need more than a few outfits, then you’ll have to size up.

These bags also aren’t ideal for travelling in cold environments. Warm clothes are bulky and will quickly fill the limited space! 

Our Favourite 25-30-Litre Backpack
Cotopaxi Allpa 28
  • Price Range: $$$
  • Best Feature: Loads of usable space and suitcase-style opening
  • Feature To Improve: Limited external pockets and nowhere to store a water bottle


Best for…

A bag in this size bracket is a traveller’s best friend! They have much more usable space than sub 30-litre bags but are generally lightweight and comfortable to carry. 

They’re suitable for short breaks or extended trips. Most backpackers can travel for months, if not years, with a backpack in the 40-46-litre range! It’s easy to fit in a week’s worth of clothes, as well as all your travel essentials. If you’re clever with the way you pack, you should also have a bit of spare room for travel gadgets or bringing souvenirs home! 

This size bag can also usually be carried as hand luggage. This means you shouldn’t need to check a bag, leaving you able to skip the extra queues and avoid waiting at the luggage carousel. 

Always check with your airline to see their full carry on limits.

Not ideal if…

For those travelling around the world and visiting extreme climates, bags in the 40-litre range might be too small. Warm clothes are bulky and take up a lot of valuable space! 

These bags also aren’t great for particularly heavy packers. While some backpackers pride themselves on carrying as little as possible while they travel, others like to bring all their home comforts. If this sounds familiar, you might want to consider a larger bag or try travelling with less.

Related: Choose the Best 40L Backpack for You.

Our Favourite 40-46-Litre Backpack
Osprey Farpoint/Fairview 40
  • Price Range: $$$
  • Best Feature: Carry on compliant and clamshell opening
  • Feature To Improve: No real water bottle pockets


Best for…

Backpackers taking long trips across many different climatic zones. The space offered inside these bags means you can afford to carry extra jumpers, coats and a few pairs of shoes along with all your other travel gear. 

They’re also good for people who want to travel with a ton of luxuries! 

The nice thing about these bags is that although they’re significantly larger than the 40-46-litre backpacks, they don’t stand out too much or feel unwieldy to carry.

If your backpack does feel cumbersome or unmanageable, check it fits correctly. Poor-fitting backpacks can be very uncomfortable to carry! 

Salkan Mainpack Top Loading
A 50-60-litre backpack is ideal for travellers heading through different climatic zones.

Not ideal if…

You want to travel hand luggage only. These bags will almost certainly need to be checked on planes. This means you’ll also need a smaller daypack for your hand luggage. 

They’re also not great if you want to be super light on your feet while travelling. Sure, they don’t feel too cumbersome but you’ll notice how much gear you’re carrying – especially if you’re trying to take local transport like buses, colectivos or moto-taxis! 

Our Favourite 50-60-Litre Backpack
Salkan The Backpacker
  • Price Range: $$$$$$
  • Best Feature: Main pack and daypack all in one setup 
  • Feature To Improve: It's heavy and expensive 

65+ litres

Best for…

Honestly, backpacks over 65-litres shouldn’t belong to the realm of backpackers. They’re for backcountry hikers who carry everything they need to survive, or for mountain trekkers taking on high altitude trips. 

Travellers who really can’t fit all their gear into a smaller backpack will enjoy the space of a 65-litre pack but its limitations will likely prove too much for most backpackers. 

Not ideal if…

A backpack of more than 65-litres will be substantially heavier than its smaller brethren. This is even true before it’s been filled. It will be made from tougher, more durable materials which allow you to carry more. But these come with a weight penalty of their own.  

When filled, you can expect a backpack of this size to weigh more than 20kg. This is an uncomfortable amount for the average person to carry! 

They can also be very unwieldy, especially if you’re trying to navigate through busy streets or use public transport. 

Our Favourite Backpack Over 65 Litres
Gregory Tetrad/Tribute 75
  • Price Range: $$$
  • Best Feature: Detachable daypack
  • Feature To Improve: It's very bulky when full
Backpack info


At the end of the day, choosing what size backpack to buy comes down to personal choice. See how much gear you have and decide from there what size bag you’ll need. 

Honestly, most of us can easily travel with a 40-litre backpack like the Osprey Farpoint or Fairview. You probably don’t need to travel with more than you can fit into one of those backpacks.

The best advice we can give when it comes to choosing a bag is: take less stuff. It allows you to travel light, avoid checked baggage fees and easily walk miles with all your gear on your back. 

Tim Ashdown | Gear Specialist

After a life-changing motorcycle accident, Tim decided life was too short to stay cooped up in his home county of Norfolk, UK. Since then, he has travelled Southeast Asia, walked the Camino de Santiago and backpacked South America. His first book, From Paralysis to Santiago, chronicles his struggle to recover from the motorcycle accident and will be released later this year.

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