Importance of backpack's size

4:07 p.m. on December 15, 2015 (EST)
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Hi, Nabil here, I am planning to buy a 65 L backpack to use as a multiday pack online because where I live, there is aboslutely no store that offers backpacking gears and such. So I had no other choice. I am a newbie here and seeking advice about the size of the backpack. It comes in S, M, L according to the torso length if Im not mistaken. Is sizing very important? What happens if I get a size bigger or smaller? 

Thank you for any response.

4:55 p.m. on December 15, 2015 (EST)
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Hey Nabil! Welcome to Trailspace.

Yes, sizing a pack for multi-day trips is as important as sizing shoes. Too big and the pack will likely slip down your hips, putting too much weight on your shoulders and back. Too small and the hip-belt won't be effective, definitely putting too much weight on your shoulders and back.

6:11 p.m. on December 15, 2015 (EST)
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Yup, it all comes down to comfort and function, both of which will be reduced with a bad fit. Torso length is pretty easy to measure and most manufacturers have sizing info available to help you figure out which of their sizes or models will work for you.

It is tough to buy a backpack you haven't tried on. Try to buy from a retailer with a good return policy so you're covered in case it doesn't work out. Don't settle for a bad fit as it will only make you unhappy on trail.

11:28 a.m. on December 16, 2015 (EST)
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I see. Thank you so much for the advice given. Here sincerely trying to learn as much as I can :)

4:38 p.m. on December 16, 2015 (EST)
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That's why we're all here, so you're in good company!

12:31 a.m. on December 17, 2015 (EST)
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Greetings Nabil,

I agree! Very important! This guide from REI explains it pretty well -

In general, a torso length of 16"-18" is a medium. Many packs have hip belts which are interchangeable to allow you to increase or decrease the size if the one that comes with your chosen torso length isn't proper. To short torso length and its hard to get the weight off of your shoulders when the hip belt is where it should be on your hips. To long and the load lifter straps and shoulder straps don't function well in concert and the pack may sway. When the torso length is correct, the preformed design contours of the pack's back panel should closely match your particular backs anatomy. I have found that the current generation of Gregory packs fit the contours of my back pretty well while their packs from say the late 80's or 90's era did not. So pack design by manufacturer and a properly fitting suspension are both important.

9:10 a.m. on December 18, 2015 (EST)
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 I bought my first pack online (a long time ago) just thinking that I wear mostly medium sized things and I didn't have an overly large or small body frame, so I must be a medium. It turns out that I am actually a small from my torso length. So when I wore the medium, the pack frame constantly hit me at the base of my head and was really uncomfortable. I dealt with it for a long time before I realized that it should not fit that way. Then I sold the pack and bought a new one that fit properly and it made a tremendous difference.

I highly advise that you get fitted for your new pack and try it on with weight in it before you buy it if at all possible.

By the way, that advice that pine sap left from REI's website is very helpful.

7:19 a.m. on December 19, 2015 (EST)
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I now see that its very important to get the sizing right. Not just the size, even the brand, some might suit me some might not. I think its best for me to find a shop and try every brand there is to get the right fit. Thank you so much for the help, very very helpful.

9:05 p.m. on December 19, 2015 (EST)
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As others have said, fit it critical. And Ashleigh's point is very important -- your torso size isn't necessarily your "regular clothes" size.

Many other factors can affect fit and comfort, but correct size is at the top of the list.

I might also suggest, as has been discussed on this and other backpacking forums many times before, that you get your pack after you get most, if not all, of the rest of your equipment. You want a pack that will fit your gear, not have to choose your gear to make it fit in the pack.

P.S. If you can't find a shop, you can order several packs from a place like REI that has a generous return policy, then you can compare packs and return the ones you don't keep. Be sure to try them on with weight and volume in them to simulate a gear load.

5:28 p.m. on December 20, 2015 (EST)
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Nabil, you dont necessarily need to try every pack. You can order a few and return them after loading and testing if it isnt right. Read the REI thread about measuring your torso and go from there. I assume you are looking for 65L total, not just main body volume. Framed? Unframed? I have no affiliations and recommend ospry for a framed pack, ULA for a lightly framed pack, and MLD for unframed packs. Granite Gear is another great company, etc. 

December 10, 2019
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