How Big is a 20L Backpack? An In-depth Guide

How Big is a 20L Backpack? An In-depth Guide

Backpack-shopping is fun and pretty easy. But if you’re a newbie with your eyes set on a 20L bag, some things might seem unclear at first. For example, why do we measure backpack capacities in liters, and how big is a 20L backpack?

Is the size of a 20L backpack the same as its capacity?

In this article, we’ll explain how big a 20-liter backpack is and give you examples of things these backpacks can hold. Then, we’ll things off with answers to frequently asked questions about 20-liter bags.  

Dive in to find out more.

What type of backpacks have 20l capacities?

 Here’s a list of backpack sizes, their capacities, and suggested uses.

Size Capacity Suggested Uses
Small packs 5-10 liters Kids bags, sports, picnics
Daypacks 10 to 30 liters Commuting, hiking, school work
Medium backpacks 30 to 50 liters Hiking, camping
Large backpacks 50 liters or more Traveling, hiking

Generally, 20-liter backpacks are best suited for light packers and short trips. With this in mind, how can you tell how big a 20L bag is?

What can a 20-liter backpack hold?

One of the top ways to understand the size of a backpack is to estimate the things it can contain. Therefore, here are a couple of things that a 20-liter bag can conveniently hold:

In practice, objects with similar volumes to those we’ve listed above will also fit a 20-liter backpack.

Understanding how to determine the measurement of a 20-liter backpack

With the knowledge of things that will fit a 20-liter backpack, let’s examine how manufacturers determine the capacity of these bags.

Generally, most backpacks have more than one pocket and compartment. Therefore, all manufacturers have to determine the volume of each pocket and compartment and then sum these volumes to get the overall volume of a backpack. 

For example, picture water being poured in all the pockets and compartments of a backpack. The quantity of water that can fill a bag is its capacity and how big it is.

Volumes are generally calculated in cubic inches. However, since this isn’t the easiest metric to understand or the universally acceptable one, this capacity needs to be represented in liters.

While representing volumes in liters, measurements are rounded up for accuracy. This means that a 20-liter backpack has a dimension of 12220.47 cubic inches.

Volume calculations answer the question of how big a 20l backpack is, which implies what it can hold. On the other hand, its dimensions show the length, breadth, and width of the items that’ll fit in the backpack.

Who is a 20-liter backpack ideal for?

A 20-liter backpack is undoubtedly one of the best capacities for daily use. In determining whether a 20-liter bag is right for you, you’ll need to consider the following factors:

1. Torso measurement: In determining the length of your torso, you’ll need to follow these steps:

Generally, you’ll want your torso length to match or be a few inches from the length of the backpack. If the length of a 20-liter bag is far larger than your torso length, then that 20-liter backpack isn’t the best fit.

2. The number of things to pack: With this factor, consider the things you can’t do without in your trip and whether the 20-liter backpack would suffice. There’s no need to get a bag a bigger capacity than what you need to get by.

3. Your intended trip length: As a corollary to the point we’ve mentioned earlier, longer trips will require you to pack heavy. 20-liter backpacks might not be the best fit for such. However, ultimately, your packing style is the most essential factor to consider.


Q1. How many liters is a regular backpack size?

Normal daypacks usually hold 20 to 35 liters and can take a sleeping bag, clothes for a few days, and a three-day worth of food. Any bag that’s bigger than 35 liters is considered medium.

Q2. Is the volume of a backpack the same as the backpack’s dimensions?

The volume and dimensions are closely related measurements of a backpack. The dimensions refer to the size of items that can fit the bag. However, the volume is the capacity that a backpack can hold without tearing.

Q3. Is the capacity of small and hidden pockets included when calculating the volume of a 20l backpack?

Yes. The summation of all sides, inner and hidden pockets, and main compartments gives the total capacity of a backpack and your answer to how big a 20l backpack is.

In conclusion

Understanding what manufacturers mean by the backpack capacities they give can be tricky, especially if you’re backpack-shopping for the first time. If you see yourself muddling up these measurements for a 20-liter backpack, then not to worry. Everything you need to know about the actual capacity of a bag is included in this article.

To give you a clearer picture, we’ve provided examples of things it can hold. With these, you should now have a great idea of how big a 20l backpack is.