Backpack Sizes and Volumes: The Ultimate Guide

By the end of this guide, you’ll know how to choose the right backpack for your next adventure.

Backpacks are essential gear for many hikers, campers, and travelers. They come in all shapes and sizes, each with unique features. With so many market options, choosing the right backpack for your needs can take time and effort. 

This comprehensive guide will teach you everything you need to know about choosing the right backpack. We’ll cover the different types of backpacks, what to look for in a good backpack, and how to choose the right size and fit for you. 

The Importance of Sizing Your Backpack

When it comes to backpacking, one of the most important things you can do is to make sure your backpack is the right size. A backpack that is too small will be uncomfortable and unable to carry all your gear. At the same time, a backpack that is too large will be bulky and difficult to carry.

So how do you know which backpack is the right size for you? Measuring your torso length is the most important factor in determining backpack size. Once you know your torso length, check a sizing chart to find the perfect backpack.

Sizing your backpack correctly is crucial for a comfortable and enjoyable backpacking trip. With a little effort, you can ensure your backpack fits you perfectly and helps you make the most of your time on the trail.

There are a few things to consider when sizing your backpack:

• Decide how much gear you want to be able to carry. 
• Take into account the dimensions of your gear. 
• Factor in your body size and proportions. 

Considering these factors, you can find the perfect backpack for your next backpacking adventure.

Related: What is Backpacking? A Comprehensive Guide for Beginners.

How Do You Measure Backpack Sizes?

Backpack sizes are typically measured in liters. The size of the backpack is usually determined by the capacity of the backpack, which is usually 20-35 liters for daypacks and 40 liters or more for larger backpacks.

To find the size of your backpack, you will need to measure the backpack’s length, width, and depth. The length is the distance from the top of the backpack to the bottom; the width is the distance from one side of the backpack to the other, and the depth is the distance from the front of the backpack to the back.

Once you have these measurements, you must find the backpack’s volume. You can do this by multiplying the length by the width by the depth. For example, if your backpack is 30 centimeters long, 25 centimeters wide, and 15 centimeters deep, your backpack’s volume would be 112.5 liters.

Now that you know the size of your backpack and the volume, you can determine how much gear you can fit inside of it. Most backpacks have a certain amount of gear they can hold, usually 60-80 liters.

If you are looking for a backpack that can hold more gear, consider a backpack made for trekking or camping. These backpacks are typically larger and can hold more gear. 

You can also use a standard sizing system. Most backpacks come in three sizes: small, medium, and large. Small backpacks are best for children and people who need to store many small items. Medium backpacks are ideal for most people, and large backpacks are best for more significant people or people who need to store more items. 

Also Read: How to Attach Trekking Poles to Your Backpack in 5 Simple Ways

How to Choose Your Perfect Backpack Size

It’s time to choose your ideal backpack now that you understand how volume in backpacks is calculated. 

You should first consider the specifics of your trip, particularly the location and length, to determine what backpack size you need.

Here is a quick guide to choosing the right size backpack, along with the most popular capacity ranges (in liters) and how they relate to typical adventure uses:

Check out this simple chart below:

0-10 Liters

Since you can only fit minimal items inside these backpacks, you will only use them for one-day expeditions. Even so, backpacks this small are designed for hikers who only intend to carry minimum gear. Packs and vests for trail running are included here. 

A 0-10L backpack can fit a water bottle, snacks, a light jacket, and first aid supplies.

10-20 Liters

The 10–20L backpacks are large enough for minimalist hikers to carry on all-day trail runs, requiring a decent amount of food to refuel. 

In a 10–20L backpack, you can fit enough food, a headlamp, a lightweight jacket, a water bottle (2 liters), and some first aid supplies.

20-30 Liters

Regarding daypack sizes, 20–30L backpacks are the largest choice, with 30L being one of the more common sizes. These backpacks are perfect companions for more strenuous activities like rock climbing because they can hold just the right amount of gear to keep you comfortable and prepared.

In a 20-30L backpack, you can fit enough food supplies, a headlamp, a small notebook, two lightweight jackets, 2L water bottles, and a small first aid kit.

30-40 Liters

If you’re planning a weekend camping trip, 30-40L backpacks are excellent options for overnight stays. However, consider what items you need for your trip when choosing your backpack. You’ll need cold food because pots are probably too big for this size bag, sleeping arrangements, and extra clothing.

In a 30–40L backpack, you can fit a sleeping bag, first aid kit, 2L water bottle, enough food for two days, a camping tent, extra clothing, and two lightweight jackets.

Read Also: How to Attach a Sleeping Bag To a Backpack Properly

40-50 Liters

A 40–50L backpack is an excellent choice if you are preparing for a trip longer than a weekend. This bag will work well for a weekend or overnight stay for average to heavy packers. When traveling internationally, backpacks that fall in the middle of this range (roughly 45L) can also be used in place of suitcases.

In a 40–50L backpack, you can fit a sleeping bag, first aid kit, a cooking pot and camp stove with fuel, a 2L water bottle, enough food for six days, a camping tent, extra clothing, and two lightweight jackets.

50-60 Liters

The 50-60L backpack provides plenty of space for food, sleeping arrangements, and extra amenities like books or pillows. They fall under the overnight or weekend trip category. You can extend this size range to account for a few extra days or extra friends if you pack light.

In a 50–60L backpack, you can fit a large sleeping bag, a first aid kit, a cooking pot and camp stove with fuel, a 2L water bottle, enough food for six days, a 3-person camping tent, extra clothing, a book or pillow, and two lightweight jackets.

60-70 Liters

Depending on the food or comfort you want, your backpack can handle more extended trips, up to about a 10-day trek. They are also appropriate for weekend or overnight trips, especially for hikers who want to make trips feel cozier. More room allows you to carry various food options, making hikes more enjoyable.

In a 60–70L backpack, you can fit standard camping gear, a large first aid kit, a 2L water bottle, enough food for ten days, extra clothing, board games, a book or pillow, and heavier jackets.

70-80+ Liters

The 70L and larger backpacks may be a great fit if you like luxury and comfort when hiking. These backpacks have a large volume, enabling you to carry extra supplies for anyone accompanying you, such as your kids or friends, as well as extra clothing, amenities, and food options. They also allow you to prepare for weather changes.

In a 70–80+L backpack, you can fit standard camping gear, a large first aid kit, water bottles, enough food for ten days, a 5-person camping tent, extra clothing, board games, a book or pillow, and heavier jackets.

Related: How to Organize a Backpack for Travel (6 Useful Steps)

What’s Next?

It’s crucial to have a backpack that fits comfortably on your back without being too tight or loose, especially if the backpack’s volume is higher.

Your torso length (not overall height) and hip circumference are the measurements you’ll need to take. 

When choosing the right backpack, consult the manufacturer’s size chart, as torso lengths are typically listed from small to extra large, with exact measurements varying between manufacturers.

And with that, you have everything you need to know to begin looking for the ideal backpack that suits your requirements. We hope this guide will help you find the perfect backpack to hit the trails confidently!