How to Measure a Backpack a Simple but Ultimate Guide 2021

You might be wondering how to measure a backpack, here is the detailed guide for you. There is no point in getting a backpack if it does not get fit properly on your body. In addition, it is useless to invest in a daypack that is too tight or too loose to be hugged by your body.

So, have a look at this guide. All the below-mentioned details are going to tell you how to get the right size backpack for yourself! We know that backpacks are the best invention on earth. But you need to choose that style and design that gets fit your body.

Also Read: How to Choose a Backpack for Hiking 2021 Ultimate Guide FOR YOUR ADVENTURES

Backpacks are available in a range of sizes, shapes, designs, and dimensions. Wide numbers of options are there. Brands have started to make backpacks suitable for large body sizes and even for small body sizes.

It even depends on your wilderness scale regarding what size and measurement of backpack you need to be getting! Check out the details now and let us know how you measure your backpack:

How to Measure a Backpack

Guide to measure a backpack

Most importantly, backpacks are usually and generally measured in two ways. Like, you can either measure them on the basis of their volume. Or you can measure them on the basis of their size dimensions. While talking about the volume of a daypack, this figure tells us that how much holding power is possessed by that pack! This volume range is measured and assessed by using cubic inches or liters. On the other hand, to measure a backpack size, you can consider it’s specific. This includes its length, width and also height, or depth.

What do we mean by Volume of a backpack?

As we have already told you that the backpack’s volume refers to and explains to us its carrying capacity. As an example, if you have got hiking backpacks, it means that their usual range will come out to be 25-liter capacity through 50-liter. The larger the size of a backpack, means more volume it will carry!

Guide to measure a backpack

How to Measure the Volume of Packs?

The process to measure the volume of backpacks is easy enough. Like, you can keep on adding the bulk in the pack, and this way, you can determine its holding capacity. This is the same method that is followed by manufacturers as well. Furthermore, the volume is determined by assessing the holding capacity of the main compartment and pockets. Some of the manufacturers even include the holding and carrying capacity of rear mesh pockets, side water bottle pockets while measuring closed storage potential. Hence, this is basically the weight-to-volume method that helps us to measure the volume of the backpacks. 

What do we mean by Backpack’s Dimensions?

When it comes to the job of measuring a backpack, then its dimensions should not at all be neglected. So, measuring your daypack dimensions is not a tough job to do. You just need to get a measuring tape and start off with this task. In addition, properly measure your bag’s length, height, as well as width. If you have bought a standard 40-liter backpack, then its dimensions will come out to be 21.3”x 12.6” x8.3”.

It is with the help of dimensions that the user can clearly determine what the actual size of his backpack is! Furthermore, the dimensions of your pack help you calculate the volume of your pack as well.

Measuring your backpack dimensions should not be ignored at all. If you do not know the actual length of your backpack, then how can you determine whether it will reach your lower body, torso, or not! Besides, these dimensions and measurements give you a clear idea of whether you have chosen a comfortable-to-wear backpack or not.

Why it is important to measure a backpack?

It is extremely important for any backpack owner to know about its carrying capacity, dimensions, size, length, width, and height. These details exactly tell you the real potential and capabilities of your daypack.

Measuring a backpack tells that it will get fit on your body or not. In addition, it gives you an idea of whether it will remain balanced on your body or might arise issues for you. If you have a small body and you have bought a big size backpack, then such a pack may bring severe backpack issues for you.

Besides, an incorrectly sized backpack might make your body topple over. It is essential to get a pack that ensures balance, comfort, and safety. It should remain comfortable to carry.

How to find the best backpack fit?

While you are on your way to shop for the best backpack fit, then these below-mentioned points should be remembered by you! Furthermore, always choose that backpack that promises to ensure the right fit. If it matches properly with your body size, then that is great. In addition, look for a pack that matches perfectly your torso length. Along with that, invest in that backpack model that is snug and hugs your hips comfortably. For more guidance, you should get in touch with the daypack fit specialists that are usually present in the stores. They can guide and advise you better which backpack fit and size suits your body.

The factor of torso length

First of all, there is this factor of torso length that plays a critical role while getting an ideal backpack fit. We have mentioned this point to you that packs are commonly available in a range of sizes. Some backpacks are small and some are extra small. In addition, some day packs are large and some are designed in an extra-large size range. In this size range, torso lengths vary as well. Now, lots of brands have included this element of adjustable torso lengths. The liberty is given to the user to adjust the torso length according to their body size and height. Moreover, this element of torso length is given the name of adjustable suspensions too.

how to fit a backpack

How to Measure Your Torso Length?

We know that there are many people out there who do not know how to measure their torso length. You can check out this guide, get the exact measurement of your torso length and match it with your backpack suspension range:

Take a flexible tape and follow all of the below-mentioned steps. You need to tilt your head forward first of all. Feel the boney bump. This boney bump is present where your shoulders are actually meeting your neck. Here the top section of the torso length can be determined.

Slide down both of your hands to the top section of the hip bones. Point your index fingers in a forward direction and keep your thumbs in a backward direction.

Now, draw an imaginary line exactly between your thumbs. Here you can assess and determine the bottom section of your torso length. After that, you can stand up straight. Get the tape and ask the helper to measure the distance exactly where your shoulders are meeting your neck to the imaginary line. This is how you can know about your torso length.

The factor of waist size

Your waist size matters a lot when determining the exact backpack fit! Try to choose a backpack whose hip belts are exactly your waist size. Most importantly, we have seen that hip belts of backpacks usually fall in the range of mid-20 inches to mid-40 inches.  Because of the current advancement made in the backpack industry, adjustable hip belts are made. This way, the person can adjust the belt according to his waist and hip size.

Some Standard backpack Sizes

As all of you have got enough information on the volume, interior, and exterior dimensions of a backpack! Now is the time that you should have an understanding of the standard packs’ sizes. This is not a restriction that each and every backpack brand follows these standards sizes. The measurements do show plus and minus ranges. The below-mentioned size ranges are mentioned just to give a rough and basic idea to the readers:

  • 8L backpack standard size is 17” x 8” x 5”
  • 25L backpack standard size is 21” x 11” x 6.5”
  • 30L backpack standard size is 21″ x13.5″ x 9.5″
  • 40L backpack standard size is 21” x 14” x 9”
  • 50L backpack standard size is 29.5″ x 13″ x 10″
  • 70L backpack standard size is 28″ x 14″ x 12″
  • 110L backpack standard size is ‎30” x 18.5” x 12.5”

Types of backpacks and how their measurements and volume differ from each other

Below we have mentioned the details of different types of backpacks and we have also mentioned how they differ from each other in terms of their measurements and volume. No matter, you have got a daypack, weekend pack or you have bought a multiday pack, and extended trip backpack- all these packs carrying capacity and measurements differ and vary a lot from each other.


We have seen this practice on the general note that daypacks volume ranges in between 20 to 35 liters. Furthermore, they are included in the category of smaller-sized backpacks. It is best to carry them if out are out for a half-day hike. In addition, these backpacks are even available in a large volume range. Some of their versions show a holding capacity of 40 liters if you are going out on long day hikes! In this backpack type, you are given enough space to keep your essentials. While you plan to hike, you need to make this thing sure that your daypack allows enough carrying capacity.

Weekend backpacks

Secondly, we have weekend backpacks that are ideal to be used while you hike for 1 to 3 nights. Their carrying capacity is around and about 30-50 liters. For long weekend backpacking trips, they are an ideal option for you. They give you ample and maximum space for storing your gear.

Multiday packs

They are the most popular types of packs if you are planning for warm-weather trips. Their carrying capacity is 50-80 liter and perfects to be used for backcountry skiing and even for 2-night trips, and overnighters.

Extended trip daypacks

Lastly, we have extended trip backpacks and their storing capacity is approximately 70 liters. A few of the versions of them possess even a larger volume. If you are out on a winter trek, then this is the suitable backpack type for you.


This is how you can measure a backpack. We have mentioned and collected extensive information for our readers. Now, the choice is up to you regarding how you utilize this information. Most importantly, do not get confused while taking the measurements of your backpack and making them synchronized with your body size and height.

If it is your first time, then take help from the backpack fit specialist. Rest, the above-mentioned guide can help you out too. We have touched and highlighted all of the important areas that play a crucial role in measuring a backpack.

For more details, keep tuned with us. And if any of the readers want to give their feedback on measuring a backpack and how to get the perfect daypack fit, then share your tips with us. Your trips and hiking times will only remain enjoyable if the backpack perfectly and ideally fits on your body.

If you get successful in getting the right backpack fit, then you will always have an enjoyable hike. However, the wrong and incorrect backpack fit will just give you a miserable hike time.

Leave a Comment

Your email address will not be published. Required fields are marked *