Whether you’re section hiking or tackling a thru-hike, getting the right fit is your ticket to striding in comfort, not wincing in pain. Let’s dive into sizing and fitting your backpack—because the trail deserves your best vibes, not your best frowns of pain!

Sizing and fitting backpacks

Consumers often buy goods based on two things: brand and price. However, the backpack for your section hike or thru-hike should be based on properly sizing and fitting your backpack. Backpacks typically come in small, medium, and large. The size is not related as much to height or build as it is to the length of your torso.

The length of your torso is important in properly sizing and fitting backpacks because the hip pads need to hug the top of the hip bones, aka the iliac crest, while the shoulder straps should wrap closely around the shoulders. The majority of the weight should sit on your hips, or you could start experiencing pain in the shoulders, neck, or upper back. So, first you want to measure your torso from the C7 vertebrae to the illiac crest like shown in the picture below. Then, you’ll compare this to the torso range charts for the particular bag you are buying. I highly recommend at least going to a place such as REI to get a good fit as some stores many not carry sizing charts. Most major manufactures will have these listed online.

• Gregory sizing
• Osprey Packs sizing
• Deuter Sport sizing

Most backpacks are designed to fit most hip sizes within the torso size, but sometimes these may fall outside of certain body sizes.  Therefore, you should then get a hip measurement, or you can try on bags if in store. Hip measurement is not the same of your waist size as the pads will be going across the gut. Here you will measure around the top of your hips, around the iliac crest in the same area you measured for your torso length. The padded part of the hip pads should not connect around the belly and should have a space of 3-6 inches.

Adjusting your backpack

Backpacks have four areas of adjustment: hip belt, load-lifter, shoulder, and sternum. Add 15-20 pounds to your pack before adjusting, as an empty pack will not sit the same as a weighted pack. Adjust so that it feels comfortable. Remember, different bags have different feels. Different bodies have different feels. Don’t just go for a brand because someone else did. If you’re spending any amount of time on the trails, you want to be as comfortable as possible. There’s nothing worse than stinging pain the whole time because your bag doesn’t properly fit.

Hip belt

Assure that the hip belt falls on the iliac crest. If your hip belt goes above or below the hip bones, you can loosen or tighten the shoulder straps to lower or raise the hip belt. Try on the bag. The belt should rest comfortably and snugly without pinching. Remember that you should have at least a couple of inches of space between the two pads (3-6 is even better). Many backpack manufacturers have interchangeable hip belts in the event that the size that comes with the pack does not fit.

Shoulder straps

While you may have just adjusted these to properly seat your hip belt, ensure that you are not tightening them so much that you are placing too much weight on your shoulders. The harness should stop 2-3 inches under the armpits. As you hike, you may have pain and pressure points. Adjust as needed to relieve the pain.

Load lifters

These two straps connect at each side of the harness to the back (see photo below of the Gregory backpack). There should be an approximate 45-degree angle when under tension. If your bag feels like it is pulling backwards, you can try tightening these. However, ensure that your bag is properly balanced. Do not over-tighten these, as it can cause pain. They should be snug but not very taught.

Note: Some smaller or lightweight packs may not have load lifters.

Sternum Strap

This strap should help keep your shoulder straps in place and allow free arm movement. It should sit an inch or so below the collarbone. If your chest feels compressed, the strap is probably too tight. You want it snug but not too tight.

Conclusion

And there you have it—your crash course in sizing and fitting a backpack that’s ready to be your trailside soulmate! By measuring your torso, fine-tuning those straps, and ensuring your hip belt hugs just right, you’re setting yourself up for miles of happy hiking. No more nagging shoulder pain or wobbly packs pulling you backward. With a properly fitted backpack, you’re free to soak in the views, chase the horizon, and maybe even do a little victory dance at the summit. So, gear up, adjust with confidence, and let the trail adventures begin! Oh, and of course, be prepared to make adjustments on the trail. I would often find myself changing the tension, especially the load lifters, from time to time.

How to fit a backpack video by Ospey Packs

For those who need a video…