You’re on the search for a new backpack. Maybe you’ve taken an interest in hiking, you’re going camping for the first time, or perhaps you simply need a rugged backpack to travel with. It’s always a lot of fun buying new gear!
But when it comes time to pick a backpack size that can accommodate the gear you need to bring, it can quickly get confusing as you try to figure out what liter number translates to your own real-world requirements.
So today, I’m giving you an in-depth guide to finding the perfect backpack size. I’ll walk you through everything you need to know—from understanding the backpack size system, which types work in various scenarios and tons of extra tips to ensure you get a backpack that fulfills all of your needs.
By the end of this article, you'll clearly understand the ideal size for your needs, allowing you to fully enjoy your outdoor adventures with confidence!
Backpack Capacity and How It Works
Your main consideration when picking a backpack is going to be its capacity. This refers to how much space is available inside the backpack to store things.
You’ll need a backpack that’s large enough to store everything you need for your trip, or you’ll end up having to leave things behind.
But at the same time, you don’t want it to be needlessly large, or it’s not going to be very comfortable to wear.
How We Measure Backpack Sizes
If you’ve been shopping in stores or online for a backpack, you’ll have noticed that size is typically measured using a number followed by the letter L, which stands for liters.
For example, a 20L backpack means that it has an internal storage area equivalent to 20 liters, which is generally quite small.
You will also commonly see sizes such as 40L, 60L, and even as high as 90L!
Now you may be thinking, surely I should just get the biggest size possible, so I’m covered in every situation, right? Unfortunately, it’s not quite that simple.
There’s a reason we put careful consideration into which size we pick. If you were to pack 20 liters’ worth of gear into a 60L backpack, it’s going to be unnecessarily bulky, and it won't hold the contents securely.
Having the weight shift around as you walk isn’t just uncomfortable; it can affect your balance too, which is especially important when hiking through rough terrain.
Additionally, when your backpack is the right size, you’ll be able to organize your things better.
Everything gets snugly packed inside and allocated to the correct compartment, so when it comes time to get things back out, you know exactly where they are.
I’ve been on several hikes myself with a backpack that was too large, only to open it up and find everything inside in a jumbled mess.
After dealing with that, it makes you appreciate the importance of getting the right-sized backpack.
Backpack Capacity: Common Ranges and Use Cases
Now you understand why we put so much thought into backpack sizes. Let’s go into a little more detail about the common range of sizes we use, what you can expect to store in them, and some common scenarios you’d use that size for.
Lightweight Backpacks (20-35L)
These are typically the smallest backpacks you’ll find and are designed for quick trips lasting 1 or 2 days, where only minimal equipment is required.
The main benefit of lightweight backpacks is that they’re super comfortable and easy to move while wearing.
This means trips that involve a lot of walking or physical activity are far more pleasurable. They’re also pretty convenient, usually having minimal extra pockets and compartments, so everything’s simple, quick, and easy to access.
|
Common Use Cases |
Items You Can Fit |
|
Day Hiking |
- 1-2 changes of clothes - Water bottle - Snacks - First aid kit - Rain jacket or light jacket - Sunscreen - Small camera or phone |
|
Weekend Getaway |
- 1-2 changes of clothes - Toiletries (travel size) - Small first aid kit - Light jacket or sweater - Water bottle - Snacks - Phone or camera |
|
Urban Travel |
- 1 change of clothes - Laptop - Documents or itinerary - Phone - Snacks - Water bottle - Small camera - Lightweight jacket |
|
Ultralight Backpacking |
- 1 change of clothes - Thin sleeping bag - Compact tarp - Lightweight cooking gear (e.g., small stove) - Food for a day - Small first aid kit - Water bottle |
Standard Backpacks (40-60L)
40L backpacks are often referred to as standard-sized because they are the most common and popular backpack size you’ll encounter.
They are a good ‘all-rounder’ and can comfortably accommodate trips or hikes that will last anywhere from 3 to 5 days. For these longer trips, you’ll typically require multiple changes of clothes, sleeping bags, cooking equipment, and food supplies.
A 40L backpack offers a great middle ground between providing extra space for all these additional items while still remaining lightweight and maneuverable.
They often feature multiple storage compartments to better organize items such as cameras or photography equipment. These backpacks offer lots of flexibility and will cover the broadest variety of scenarios.
|
Common Use Cases |
Items You Can Fit |
|
Hike in Moderate Terrain (3 days) |
- 2–3 changes of clothes - Lightweight sleeping bag or liner - Compact stove and basic cooking gear - Snacks and lightweight food for 2 days - Headlamp and extra batteries - Rain jacket or poncho - Water bladder and filtration system - Navigation tools (map, compass, or GPS device) |
|
Remote Work or Business Travel (3-5 days) |
- Laptop and charger - Work documents and notebooks - 3–4 changes of formal or casual clothes - Travel-size toiletries - Lightweight jacket - Snacks and a reusable water bottle - Power bank for charging devices - Noise-canceling headphones - Travel pillow (optional for flights) |
|
Outdoor Photography Excursion (2-3 days) |
- DSLR camera and additional lenses - Lightweight tripod - Extra camera batteries and memory cards - Protective rain cover for the camera and backpack - Snacks and water bottle - Rain jacket or windbreaker - Lightweight gloves (for colder locations) Notebook or tablet for notes or editing photos Small first aid kit |
Expedition-Level Backpacks (60L+)
These are your big boys and are designed for outings that you might consider advanced or extreme.
This includes multi-week hikes, trips with extreme weather conditions, or difficult environments that require specialized gear such as medical supplies or heating equipment.
They’re often rugged and durable, with large amounts of storage space for extra items like cooking gear or thicker sleeping bags with better temperature ratings.
These backpacks are designed to carry heavy and bulky equipment, so they typically have features to assist in distributing the load evenly and reduce back strain, such as frame reinforcement or padded straps.
Needless to say, these backpacks are serious pieces of kit made for experienced adventurers traversing the most demanding environments.
|
Common Use Cases |
Items You Can Fit |
|
High-Altitude Trekking in Cold Weather (5-7 days) |
- Insulated sleeping bag rated for-10°C or lower - 4–5 changes of thermal and weather-resistant clothing - Down jacket and rain shell - Portable stove and fuel - Freeze-dried meals for 5–7 days - Water filtration system and bottle - Ice axe and crampons (if required) - Emergency blanket and survival whistle - Headlamp with extra batteries - Trekking poles |
|
Backpacking Expedition in Tropical Terrain (5-7 days) |
- Lightweight, moisture-wicking clothes - Mosquito net and insect repellent - Rain jacket or poncho - Waterproof dry bags for gear - Water filtration system and water bottle - Food for 5–7 days - Compact cooking gear - Lightweight tent with good ventilation - Sunscreen and wide-brim hat - First aid kit with tropical-specific medicines (e.g., antimalarial tablets) |
|
Winter Backcountry Camping (4-6 days) |
- Winter-rated sleeping bag and insulated sleeping pad - 4-season tent - Snow shovel and snow stakes - Stove with cold-weather fuel - High-calorie food (e.g., nuts, dried fruit, and freeze-dried meals) - Insulated clothing layers (base layer, mid-layer, and waterproof outer layer) - Gaiters and insulated boots - Hand warmers and thermal gloves - Headlamp with extra batteries - Avalanche safety gear (beacon, probe, and shovel) |
Now that you have a solid idea of which size backpack is going to be most appropriate for your adventures, it’s time to explore other key features that can make your life easier during difficult excursions or harsh weather conditions.
Considerations When Choosing the Right Size Backpack
Overall storage volume will always be your primary consideration. The last thing you want is to be left not being able to bring a vital piece of equipment because you just couldn't fit it in your bag.
Or you didn't have room for that extra warm sleeping bag because it was too bulky, and now you’re freezing.
These things are easy to overlook, especially if you're new to outdoor adventuring. So let's take a look at what you need to factor in based on the type of trip you'll be taking.
Core Equipment Considerations
The equipment and supplies you bring are ultimately dictated by the trip duration and climate conditions. So the first thing to think about is how long your trip will be.
If it’s just a 1-day hike and you’ll be back by sundown, just snacks or a simple lunch will suffice, and a small backpack will easily get the job done.
A longer trip of 3-5 days will require more equipment in the form of extra food, perhaps cooking supplies, and a sleeping bag.
Think carefully about your trip duration and how much food you’ll need to take to make sure you’re well-stocked the whole time.
You’ll also want to factor in climate; traveling on a hot summer hike will allow you to pack fewer clothes and a thinner sleeping bag. But you’ll also need enough room for water.
But when traveling during the winter, you’ll often need considerably more clothing, including thick jackets and insulated sleeping bags. You may even need dedicated climate-focused equipment such as snowshoes or crampons.
Finally, you should think about what devices and electronics you need. Do you need to power cameras, smartphones, lights, GPS devices, or heaters?
How to Stay Powered While On-the-Go
Electronic devices aren’t just luxuries that you can enjoy for convenience. These days, backpackers use them as essential safety devices.
A GPS will prevent you from getting lost if you veer off the beaten path, and a smartphone with satellite capabilities such as Apple’s Emergency SOS will allow you to call for help even if you’re far beyond regular cellular service.
For that reason, backpackers take keeping their electronic devices charged and ready to go very seriously. To do that, they will most commonly use a portable backpack power station or generator.
If you’re taking a shorter trip and want a lighter load, the BLUETTI Handsfree 1 Backpack Power Station is a fantastic option.
It’s a super comfortable and travel-friendly 42L backpack that seamlessly integrates both a power station and solar charging capabilities into a durable and ergonomic design. It looks cool, too!
Key features include:
- Up to 30 kg carry capacity with no loss of comfort.
- Charge up to 5 devices simultaneously.
- Automatically activates charging when sunlight is detected.
- Breathable and water-resistant.
- 268.8Wh battery with 300W power output. It can fully charge your smartphone from empty to full 22 times in as little as 30 minutes.
The BLUETTI Handsfree 1 is a great choice for photography trips and drone exploration, or it can even function as an off-grid office thanks to its compartmentalized internal storage. If hiking is more your thing, the solar panels are excellent for charging the battery while you walk. You simply focus on enjoying your hike, and it’s going to be charged up by the end of the day.
Regular backpacks aren’t very water-resistant, and the lower-quality materials can quickly develop punctures or abrasions from things like tree branches or rocks. This makes it pretty risky if you’re taking expensive recording equipment with you.
But the materials on the BLUETTI backpacks are splash-resistant, and the zippers are completely waterproof, so all your important electronics and clothing will be kept nice and dry. Then, if the weather is extreme, it comes with a rain cover for complete protection in the most extreme of conditions.
If you plan on taking a longer trip and need extra storage. The BLUETTI Handsfree 2 Backpack Power Station is going to be a better option.
It's got a bigger battery and a higher power output. You can keep yourself up and running for longer or even keep your entire party powered!
- 60L storage size for more gear.
- Larger 512Wg battery size and 700W output.
- 200W solar input for incredibly fast charging; it will charge the battery to 80% in as little as 1.5 hours.
This larger battery is going to be able to handle more demanding electronics, such as heaters and hotplates. So, for longer hikes where camping and cooking are involved, this will handle it.
Both backpacks come with a generous 5-year warranty, so you'll have no qualms about taking them out into the wilds with you.
Now you understand which size backpack you need and the essential requirements, such as power, we’re nearly there!
But there are a few more things you’ll want to make sure your backpack has before you can be 100% sure it’s the perfect one for you.
Picking the Right Backpack: Extra Tips
We don’t want to overwhelm you with endless tips and considerations. But the truth is, it’s worth taking some time to make sure your backpack ticks as many boxes as possible.
A good backpack can make your trip considerably more enjoyable. So here are a few handy things to think about when choosing yours.
Back Support and Comfort
You're going to have your backpack on a lot, so you want to make sure it's going to be worn comfortably for extended periods without making your back tired.
Trust me, nothing is worse than finishing the day with a bad back.
Good manufacturers, such as Bluetti, put careful thought into making a good back support system that distributes the weight evenly. This includes features like padded straps that reduce shoulder strain and chafing, a hip belt that provides support between you and the backpack, and breathable materials that promote airflow and minimize sweat build-up.
These things might not seem that impactful at first. But on a long trip, they help massively in reducing fatigue accumulation.
Built to Last
Good backpacks are designed to withstand some abuse. They’re going to be used outside in the rain and wind, and they’ll be thrown on the ground, so it’s important that they are durable enough to withstand the rigors of outdoor use.
Check that the bag you're buying is water-resistant. Good backpacks (such as those offered by Bluetti) even come with a rain cover, so you can have absolute peace of mind that your electronic devices, battery packs, and food will not be compromised.
Keeping Organized
Regardless of whether you’re a photographer, hiker, camper, or all of the above, you’re going to be bringing some equipment.
Having a backpack that’s designed with organization and accessibility in mind is very useful. It can help with keeping electronic accessories secure by storing them in safer areas of the backpack, which are less likely to be bumped during your travels.
A good backpack will have multiple compartments that are easily accessible, so you can get to what you need quickly.
If it starts pouring with rain, the last thing you want to be doing is emptying the contents onto the ground to find a rain cover.
A backpack that facilitates all the key points mentioned above is going to allow you to adventure in comfort and avoid all the frustrations that come with using an incorrectly sized or poorly thought-out backpack.
Ready for the Road
You’re now completely in the know when it comes to backpack sizes, and you have a solid understanding of important features to look for when choosing the perfect storage format for your things!
You should choose a backpack that has an appropriate storage size for the length of your trip and how much gear you’re going to need. It needs to have good back support for comfort and reducing fatigue, and it should be durable enough to withstand the elements. Finally, it needs to have enough compartments for you to organize everything you need in a logical and accessible way.
Your backpack has a massive influence over the comfort and quality of your adventures, so it’s important to invest in the highest quality possible.
Solutions that tick all of these boxes, such as the Bluetti Backpack with Power Station and Backpack Generator, will ensure you’re well taken care of during your adventures.
Head on over to Bluetti’s official website for more information on these backpacks. You’ll find some super useful expansions and accessories and more detailed specifications on the battery solutions.
FAQ:
How many liters should a backpacking backpack be?
A 20L backpack is ideal for a day trip or overnight stay; a 40L backpack works great for a 3-5 day trip, and a 60L backpack is better suited for longer trips of up to a week or more.
Is 40 liters too big for a backpack?
This depends on the length of your trip and how much gear you need to bring. A 40L backpack might be too excessive if you're just going sightseeing and will come back the same day, but if you plan to stay somewhere for a few days, it should be just right.
Is 60 liters too big for a backpack?
60L is generally considered a large backpack. It’s designed for longer expeditions or harsh weather conditions, such as winter hiking.
If you’re just going away for a few days, you should be able to get away with a 40-liter backpack.
Is 40 liters enough for 6 months?
A 40L backpack has ample room to fit all your essentials. Clothes, electronics, charging solutions, etc.
If you plan on using a 40-liter backpack for an extended period, such as 6 months, you may want to consider an ultralight packing strategy. This involves picking clothes and items that minimize bulk and are multi-purpose.
Stick to the absolute essentials and adopt a minimalist mindset to ensure you’re not filling up your limited space unnecessarily.
