You’ll need a backpack whether you’re going to school, college, travelling, hiking, or simply exploring the environment. However, when purchasing a backpack, it is important to assess the backpack’s storage capacity and figure out the right backpack for your needs.  

If you’re looking to buy a 40-liter backpack, but you aren’t sure how big is a 40 liter backpack, you’ve come to the correct spot. This post will provide you a detailed breakdown of how big is a 40 liter.

How Big Is A 40 Liter Backpack? Quick and Detailed Understanding

Take a deep breath and let go of your worries as we walk you through a full description of a 40-liter backpack that will help you in choosing the right size. At the end of this article, you may learn how to measure your bag, which size is best, and, most importantly, how big is a 40 liter backpack.

How Is Backpack Capacity Measured?

Capacity specifications are one of the most important features in a backpack. So, first and foremost, let’s talk about how a backpack’s capacity is assessed in order to get a notion of how big a 40l bag is.

 When determining the size of a backpack, two sorts of measures are commonly used: dimensions (real height/length/width measurements) and volume. The size of the backpack is determined by its dimensions, whilst the volume of the backpack determines its total carrying capacity.

In general, you may calculate volume by multiplying the length, breadth, and depth of each compartment in the backpack and then adding all of the volumes together to achieve an accurate result. While measuring the volume of the compartment, the manufacturer measures the capacity of all pockets close and open also.


For understanding the capacity of a 40 liter backpack you must understand how it is measured. You can measure the dimensions of a backpack using measuring tape or scale. So measure the all three dimensions, length, width and depth of each compartment and then multiply them together. This gives us the volume of each compartment and then the volume of each compartment is sum up together.

These measurements are in cubic inches or centimeters, and are then converted to liters for the convenience of the user. In most circumstances, the measurement is rounded to the nearest decimal point; therefore it cannot be 100% exact.

 Most manufacturers use a standard method to calculate the capacity a backpack. This formula is the product of length, width, and depth (in centimeters) divided by 1000.

The average dimensions of a 40 liter backpack are 9.6″x13.8″x 9.8″ inch. The Volume of a 40 liter backpack is 2440.95 cubic inches.

40 Liter Backpack is Ideal Size

A 30 liter backpack can be a bit small to pack all of your stuff that you need for hiking, camping and traveling. A 50 or 55 liter backpack, on the other hand, can easily accommodate all of your belongings, but it would be too huge, and most airlines require that backpacks larger than 45 liters be checked. So, 40 liter backpack is the best option for hiking, traveling and camping.  A 40 liter backpack allows you to put most of your essentials in it and enjoy your trip. On the other hand it is not too large to manage and carry.

What Can You Pack Into a 40-Liter Backpack?

  If you travel a lot and go to the places where the weather is sever, you should consider backpacks with a capacity of 40 liters or more. They’ll have ample space for all of your belongings, including clothing and food. In this range, a backpack may comfortably hold thirty to thirty-five energy drinks.

 In general, a 40-liter backpack may accommodate the following items:

  • 2-3 spares set of clothes and
  • 3 pairs of shoes
  • Several pairs of socks
  •  If necessary, a jacket or sweater
  • Laptop, if your backpack has a sleeve for it
  • Camera
  • Writing utensils
  • A bag for carrying toiletries,
  • A towel
  • Headphones and Powerbank
  • Cords & Cables
  • Tablet
  • some snacks
  • A magazine or two and a Book
  • Maps
  • Keys
  • Passport
  • Wallet
  • Sunglasses
  • Umbrella

This is not a standardized or unified list. However, this is a general list that you should be able to fit into your 40l backpack. Depending on your needs, you may change a couple of these products with ones of your choice.

Most of the 40 liter backpacks have straps at top or bottom. So, if you’re going camping or hiking and have a tent or sleeping bag, you can attach them to these straps. You may also use the straps and clips to attach more items to your bag.

What Is It For?

A backpack with a capacity of 40 liters is termed a large backpack. As a result, a 40-liter backpack is regarded to be appropriate for travel, hiking, camping, or backpacking where multiple days’ worth of goods is required. A 40-liter backpack is large enough to hold all of your belongings without looking overly bulky.  

In addition, if your trip includes an airline flight, the backpack’s capacity should not exceed 45L. These rules do not apply to all airlines, but they do apply to 50% of them.

As a result, we can easily recommend a 40-liter backpack. It’s not too big or too little, and it strikes the proper balance. You won’t have to worry about leaving anything important if you choose a 40-liter backpack, and the bag won’t be too heavy to carry once you’ve packed it. There will also be no luggage issues because a 40L bag is under the airline’s weight limit.


 The weight of a backpack is sometimes disregarded, despite the fact that it is crucial. Material, Hardware, and Padding all contribute to the backpack’s weight. The back and shoulder straps of most 40-liter backpacks are cushioned. The hip belt straps on some of them may even be cushioned.

A 40-liter backpack does not have a definite weight; however, it is estimated to be between four and six pounds. Some 40-liter backpacks with no padding and made of ultralight polyester or nylon fabric can weigh as little as one to three pounds.

Things To Consider When Buying a Backpack

Before purchasing a 40-liter backpack, you should consider the following factors.

  • The amount of goods you intend to pack
  • The number of pockets in the backpack
  • Your torso measurement (backpack length should be equal to or less than your torso measurement)
  • Shoulder straps that are padded and breathable


We have discussed the size and the volume of 40 liter backpack. Now, you know how big is a 40 liter backpack and you have an idea of whether this backpack is good for you or not. A 40 liter backpack neither too small nor too large. It has plenty of capacity while also being comfortable to carry. So it is ideal for a variety of outdoor scenarios such traveling, hiking and comparing.

What Size Backpack do I Need?

Because various people use backpacks for different purposes,so backpacks come in a variety of shapes and sizes. Before purchasing a backpack, you should determine why you are purchasing it. We explained how big is a 40 liter backpack in depth in the article; now, in the chart below, we show the capacity, dimensions, and suggested usage of various sized backpacks.

 SizeCapacityDimensions (Height x Width x Depth)Suggested Uses  
Mini and Small Backpacks (6 -10 Liters)8 Liter17” x 8” x 5”Days Out / Kids Bags / Sports
 10 Liter12.6″ x 9.45″ x 5.11 
Daypacks (10 – 30 Liters)13 Liters16″ x 10″ x 5″Commuting / Hiking / Day  Walks
 15 liter17”x10”x5.5 
 20 Liters19″ x 11″ x 6″ 
 25 Liter  21” x 11” x 6.5”   
 30 Liter  21″ x13.5″ x 9.5″ 
Medium Backpacks (30 – 50 Liters)35 Liter21.5 x 13.5 x 7.5Overnight Trips/Camping/Hiking
 40 Liter21” x 14” x 9” 
 45 Liter22.4 x 14.17 x 8.66 
Large Backpacks (50 Liters +)50 Liter29.5″ x 13″ x 10″Travelling/Backpacking/Expeditions