Backpacks are one of the most beneficial items on the planet since they allow you to carry your belongings comfortably and easily. Backpacks are available in a variety of designs, forms, styles, and sizes to meet your personal and professional requirements.

There is a backpack size and design for every situation, from hiking in the woods to working in the office. You want to get a 20 liter backpack, but you’re not sure how big is a 20 liter backpack? This backpack size guide will tell you everything you need to know about a 20 liter backpack size, so your problems are over!

How big is a 20 Liter Backpack: A Complete Guide

Take a deep breath and relax; we’ll walk you through everything, from how big is a 20 liter backpack to determine the estimated capacity if the manufacturer hasn’t specified the bag’s volume.

How to Measure Backpack Dimensions and Volume

Backpacks are measured in two ways: their dimensions and their volume. Measurements of the dimensions of backpack (length, width, height or depth) tell us about the size of the backpack. The volume of a backpack, on the other hand, indicates how much it can store. The volume is measured cubic inches or liters.

Backpack Volume

The volume of a backpack refers to its capacity. A backpack’s volume can be calculated by multiplying its dimensions by a formula. The majority of manufacturers provide information about the size and volume of their backpacks. The volume of a backpack includes all storage compartments and pockets on the interior and outside. Some companies also include the open pockets on backpack’s exterior, such as its mesh pockets for water bottles, in the volume.  

Backpack Size

The backpack size refers to its dimensions specifically its length, width and depth. Moving on to its dimensions, the 20 liter backpack measures approximately 43cm*28cm*48cm or 17*11*19 inches (L*W*D). The size of a backpack is crucial since it determines how it will sit on your body.

 20 liters are also 1,220 cubic inches in size.

Calculating the Capacity Of A Backpack

It’s frustrating when manufacturers don’t provide information regarding a bag’s capacity. You’ll have to shop blindly or try to locate any information about a backpack’s overall volume.

You can calculate the volume of a bag on your own – it’s really easy, but you’ll only get an estimate. The formula is very simple and easy that is the product of length, width and height.

The main issue here is that you can only get a perfect result when you are looking at a smooth box. Backpacks are typically oval-shaped at the top and square-shaped at the bottom, so you’d have to do fractions and other calculations to achieve the best outcome. Because I doubt anyone has the time or energy to do so. For doing so can use a basic online calculator.

What You Can Put In a 20 Liter Backpack?

Backpacks are much larger than they appear, especially those with numerous external pockets and compartments. The total capacity of the backpack includes the capacity of each and every pocket. So, if you want a bag with a large main compartment, you should opt for one that doesn’t have a lot of exterior pockets.

The best way to understand how big is a 20 liter backpack, is to put things in it. You can put the below-mentioned things in 20 Liter backpack:

  • Two T-shirts
  • One Hoodie
  • One Shirt
  • Laptop up 15″
  • One Average-Sized Water Bottle
  • One Diary/ Notebook
  • A pen
  • Headphone

Objects with a volume comparable to those indicated above can readily fit inside a 20L backpack.

A 20 Liter backpack will weigh around 810g.

What it is for

Generally a backpack with a capacity of 20 liters is termed a small backpack. As a result, it can be used for activities requiring the transport of a day’s worth of gear. These activities include anything from hiking and climbing to commuting, travel, and school.

Backpacks with a capacity of 30-50 liters are ideal for longer adventures and even shorter ones, as long as you don’t load them up with too many bulky goods. You’ll need at least a 50-liter backpack if you’re carrying substantial gear (for hiking or climbing).Backpacks above 50 and 60 liters is perfect for long adventurous traveling and backpacking.

Why is Size of Backpack Important?

Understanding the size of a backpack is vital when buying one because it indicates its potential as well as its limitations. Because people have various needs and use backpacks for different purposes, there is no one-size-fits-all backpack that is ideal for everyone and outperforms the competition. Always choose a backpack that fits snugly and adequately accommodates your needs.

 A backpack that is either too small or too big for you can cause severe back discomfort since the weight of your load will not be balanced. An inappropriately sized bag can even cause you to fall over in the worst-case situation. When you’re out in the wild and distant from medical help, you want to invest in comfort and safety.

 As a result, the ideal backpack is one that can accommodate just a little bit more than you want to carry while also being comfortable to wear.

How To Choose The Right Backpack

There are different types of backpacks, you should think about a few key considerations before deciding on one. When choosing a backpack size, I always advise to think about two things: how much items you want to carry and your body shape.

 Here are some tips to help you find the ideal backpack:

Your Torso Type

The size of the pack vs. the size of your torso is the first thing to think about. The backpack should be around the same size as your torso. Because we buy backpacks for comfort, choosing one that is too large or too small for your torso will be inconvenient. With the help of a measuring tape and a friend, you can determine your torso size.

 If your backpack has a waist belt, it should be slightly above your hips for the best fit – if it’s too low, it won’t fit well, which means it won’t do anything to transfer weight to your hips. And the sternum strap should be above your chest.


The volume of the backpack is tied with the items you plan to carry with you. So if you want to carry bulky stuff you need a big bag or if you want to carry your daily work essentials you need a daypack. Also keep in mind the weight of items you intend to carry and how much weight your pack can bear as some items are less bulky but heavy.

Packing Style

If you intend to carry light but bulky items such sweater, jacket and warm clothes you should adopt suitable packing style for packing many items in your pack. If you just put your stuff without proper rolling or folding them you wouldn’t be able to pack much stuff in your pack. Choose a backpack with multiple compartments, so that you can store your things in an organized manner. So invest in pack that suits your packing style as packing style matters much.


You can’t compromise on comfort it doesn’t matter for what purpose you use your pack. So away go for backpack that properly fits you and offer maximum back support and comfort. If you choose a backpack that isn’t comfortable you would just prone yourself to many dangers such back pain, shoulder pain, sore shoulders and neck pain. For extra comfort, choose one with padded shoulder straps and a hip or chest strap.


  • If you wear backpack for a long time, then choose one with a ventilated back to keep your back cool.
  • If you use a tablet or laptop, then choose a backpack with a tablet or laptop compartment to prevent scratches.
  • If security is your concern, then go for an anti-theft backpack.
  • If you use your pack for outdoor activity and there are chances of rain or snow then choose a waterproof backpack.
  • If you have a bad back, choose a pack with a comfortable suspension system and maximum back support.
  • If you plan to use your backpack as a work bag, choose one that is sleek and professional in appearance.
  • If you are color-obsessed, buy a bag that complements the majority of your wardrobe.



The best backpack for you is the one that ticks all your boxes and that has plenty of space for the items you consider necessary. I hope I covered everything you were curious about  how big is 20 liter backpack– if not, just let me know and I’ll be sure to go back and edit the post!