Measure Your Torso for Backpack Size Fitting

Unsure how to measure your torso for backpack fitting? Never fear! In this guide, we explain how it’s done and provide additional tips on how to find the perfect pack for you, whether you’re buying your backpack online or in the store.

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Backpack Sizing 101: Torso Length

Wondering how to measure the length of your torso?

You’re in the right place! In this guide, we will be covering the following:

    • Why having the right size of pack matters
    • Step-by-step instructions to take a torso measurement for a backpack
    • Other tips to help you find the perfect pack size for a daypack or backpacking pack

There are many things that go into the making of a great backpack. However, when push comes to shove, the factor that has the greatest bearing on how suitable any pack is for you is how well it fits.

Unlike shoes, backpacks don’t come in a wide range of sizes – in most cases, the options are limited to small, medium, and large. So how do you know which is best for you? It all comes down to torso length.

In this guide on how to measure your torso length for a great backpack fitting, we explain all!

Why Having the Correct Size of Backpack Is Important

Having the right size of backpack is important for a few reasons:

  1. It will ensure that the appropriate percentage (around 80%) of the backpack’s weight is on your hips, and 20% on the shoulders.
  2. This distribution of weight prevents shoulder straps from digging in and helps you maintain good, healthy posture.
  3. It reduces the risk of chafing where the base of the pack rests against your hip and back.
  4. It ensures your load is more evenly distributed, which improves balance while you’re on the move with a heavy pack.
  5. It is, in short, way more comfortable!
Man carrying large backpack with sleeping bag attached
Having a well-fitted backpack is increasingly more important the heavier your load gets!

What You’ll Need

  • A friend
  • A flexible tape measure
  • Roughly 2 minutes of time

How to Measure Your Torso for Backpack Fitting 

1. Locate Your C7 Vertebra

Your C7 vertebra is located between the shoulders at the base of the neck. It is the most convex of the vertebrae so sticks out a little more than the others when you tilt your head forward. It is often described as a ‘bony bump’.

Locating the First Point at the top of the Back to Measure Torso Length
The C7 vertebra aka that bumpy bit when you lean your neck forward. ©Kieran Cunningham/My Open Country®

2. Locate Your Iliac Crest

The iliac crest is found at the top of the hip bones. To locate it, slide your hands down your rib cage slightly behind where your arms would hang in a resting position. When you hit a large bone at the top of your hip, you’ve found the iliac crest (the shelf of the pelvic girdle). This is the same spot used to measure your hip size.

3. Find the Appropriate Point on Your Lumbar

With your thumbs pointing backward from each hip bone and index fingers pointing forward, slide your hands inward to the base of your spine, or trace an imaginary line to this spot. This is the second point used to measure torso length.

Locating the First Point at the top of the Back to Measure Torso Length
Where your thumbs meet is the position of the second point to measure to. ©Kieran Cunningham/My Open Country®

4. Measure Your Torso Size

Now, have a friend measure between the two points we have identified with your measuring tape. 

5. Use Torso Length to Find Your Backpack Size

With your exact measurement in hand, you can now head to the store (or online) and start the search for the perfect pack! Most brands will display a size chart alongside the pack’s specifications.

6. Dial in the Fit

Once you’ve bought your pack, there are still a few tweaks you can make to boost the comfort of your pack and fine-tune it for an optimal fit.

First up, the load lifters. As the name suggests, these are designed to take some of the weight (i.e. “load”) off of your shoulders. They are found just above your collarbones and these shoulder straps pull the weight back off the shoulders by being attached to the top of your backpack.

Close up of backpack shoulder straps and load lifters worn by a hiker
Get a friend to help adjust the length of the load lifters. ©Kieran Cunningham/My Open Country®

Secondly, the sternum strap. This is the thin strap that connects the shoulder straps across your chest. While many hikers and backpackers are apt to leave this uncinched and dangling, adjusting it so you have a snug fit, and cinching it, will help ensure your straps stay squarely on your shoulders and centralize your load.

Thirdly, the torso length adjuster. Many internal frame packs have adjustable torso lengths, meaning they can be calibrated to fit longer or shorter torso lengths.

Finally, the hip belt. Because most of your load will be carried on your hips, you want to ensure that your hipbelt buckle is fastened while you walk and the belt itself is snug, but not tight, against your belly. Doing so will ensure your pack doesn’t bounce around as you move and keep the weight of the pack off the shoulders. 

Hiker carrying bear spray in a holster attached to his bags hip strap
Make sure your hipbelt is fastened when you are walking.

Happy Hiking!

Finding the perfect fit when buying a backpack is essential to enjoying a happy time on the trails. Because everybody is different, the only way to ensure you get the best fit for your body is to follow the above steps and match this to the size of your backpack-to-be.

If you liked his post or have any questions, let us know in the comments box below. And if you know of anyone else in the market for a new pack, send them this way!

Last update on 2023-01-27 / Affiliate links / Images from Amazon Product Advertising API

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Kieran James Cunningham is a climber, mountaineer, and author who divides his time between the Italian Alps, the US, and his native Scotland.

He has climbed a handful of 6000ers in the Himalayas, 4000ers in the Alps, 14ers in the US, and loves nothing more than a good long-distance wander in the wilderness. He climbs when he should be writing, writes when he should be sleeping, has fun always.

Kieran has taught mountaineering, ice climbing, and single-pitch and multi-pitch rock climbing in a variety of contexts over the years and has led trekking and mountaineering expeditions in the Alps, Rockies, and UK. He is currently working towards qualifying as a Mountaineering and Climbing Instructor and International Mountain Leader.

Kieran’s book Climbing the Walls—an exploration of the mental health benefits of climbing, mountaineering, and the great outdoors—is scheduled for release by Simon & Schuster in April 2021.

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