Pack Size Question

I am looking to buy a backpack for my son who is in Boy Scouts. He will be doing some high adventure outings over the next several years, so I would like something that may be able to grow with him. I'm not sure what size (liters) pack we should be looking at. He is 14 years old and is 5' 8.5" tall and growing. I don't want to break the bank either. Any help with pack size and adjust-ability is greatly appreciated. The last time I bought a pack was when I was in Boy Scouts and it was an external frame.

38L pack should suffice, any brand any model would work for him. He’s gotta carry it, though

It’s important that the pack be appropriately sized for his torso length. Given that he is still growing, I doubt you will find a pack that he can use indefinitely. My suggestion is to buy good, used gear, which are plentiful.

edit to add..

you might get away with buying one pack if his torso is already 20” or close to it.

medium pack, 18-20”
large pack, 20-22”

Thank you for the input. I will look up how to measure his torso. I was looking at REI's website and they have some good deals on packs now.

I used to work wilderness therapy and we used osprey for students, mainly because they had a good return/repair policy and most youth packs were easily adjustable. I don't use the brand personally, but most youth type programs I've worked at tend to use osprey.

some of the granite gear packs have an adjustable torso length and hipbelt size

Is he doing Philmont or just weekend trips with the Troop? While I love my Granite Gear Crown2 60 and got it on sale it is not a pack for a Scout.
I’d look into some of the WalMart Ozark Trial packs or a Gregory or Osprey 50L on sale. As some have already suggested measuring his torso will be a huge help in finding the right pack.
A rain cover for Scouts is a must especially if your son is paired with a less experienced Scout and tent setup takes 10 minutes or more.

The Ozark Trail packs look like a good deal. I don't think I'd use one for a long distance hike, but for the weekend or week long trips your son is likely to do in the next few years, it would be fine. In a few years if he's still interested, then start to upgrade the equipment.

We had this exact issue a couple of years ago -- young friend who was a Boy Scout, needed a pack for backpacking, adventure trips, and an overseas trip. He ended up with an Osprey Volt 60, a 60 liter pack that has an adjustable torso. It fit him well at the low end of the torso adjustment range, and as he grows (he's in college now) it has continued to fit well.

60 liters is very reasonable for Scouting, and the weight of just over 4 pounds is also reasonable. The sort of ultralite packs that I like are too specialized for long distance trail hiking -- he needed something more durable, larger capacity, etc. The pack was $200, tho I think we waited for an REI sale coupon and saved 20%.

If you're near an REI bring him in for a pack fitting. We pack-fit free for all ages and this will ensure (a) it would fit him well now and (b) he'd be able to grow into it. If you're not looking to break the bank, our Flash series is great. This is not an ad, I just love what we do :)

ULA equipment makes their circuit pack in an adjustable torso length for kids. The circuit is a fantastic pack from a great company.