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REI Tarn 40

The REI Tarn 40 pack instantly impressed us with how it looks and feels. I have always loved REI backpacking packs for adults, and this one for children doesn’t sacrifice the quality. It is a great size for backpacking for kids from approximately age 8 to 12+.

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The ripstop nylon material is thick and durable, this pack will stand up to whatever is thrown at it. The placement of all the compression straps is great and I especially like the ones on the sides.

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Tech Specs of the REI Tarn 40

  • Volume: 40 Liters
  • Weight: 2 lbs 10 oz
  • Dimensions: 24″H x 12″W x 9″D
  • Hydration Compatible: Yes, up to 3L, no reservoir included
  • Fits Torso Length: 12-16″ (*We don’t think it fits shorter torsos quite as well as other packs the same size)
  • Fits Waist/Hips: 22-36″
  • External Pockets: 4 outer pockets (2 stretch mesh, one front stuff, one top) plus hip belt pocket
  • Material: 420D ripstop recycled nylon
  • Ages: 6-12+ (*We recommend 8+)

Key Features of the REI Tarn 40

  • Adjustable back panel and side compression straps combine to provide a customizable fit
  • Padded shoulder straps and hipbelt provide a comfortable carry
  • Large stuff pocket in the front provides quick-access storage for an extra layer
  • Removable top-lid pocket allows options for organization
  • Loops on the front allow bungees or clips to be attached
  • Made to reflect REI’s love for people and the planet through the use of recycled and bluesign®-approved materials
  • Adjustable sternum strap with rescue whistle

My son is an average-build 6.5yo and has a torso length of just over 12″, and the pack just barely fits him. He can carry it comfortably when it is adjusted to the absolute smallest setting; but he feels more of a backwards pull with it than with other packs of this size. I wouldn’t recommend this pack for children younger than 7 or 8.

Because the pack has so much space but already weighs over 2.5 pounds, my 45# kid can only pack about 6.5 pounds of gear in it before he’s at 20% of body weight. At 10% body weight you’d add just 2 additional pounds!

The pack/weight ratio is going to be an issue with most 40-liter kids packs. The Tarn 40 is in the same weight range its 40L counterparts. This is another reason it’s better suited towards kids who are a bit older than it’s minimum stats.

Best Uses for the REI Tarn 40


This is a backpacking pack, and is likely to be a child’s first or second pack beyond a daypack when they begin to carry their own gear. I wouldn’t rush into the Tarn 40 for a smaller child, but children 8-10+ will find it fits well and provides all-day trail comfort thanks to ample padding!

There is plenty of space for a child to carry most of their gear inside; and while one main compartment doesn’t allow for a lot of organization options, what they’ll probably be carrying is their sleeping bag, a stuff sack filled with extra clothes, and snacks in the top and front pockets.

This pack (well, most packs) gets my kids excited about going into the backcountry. The underside of the lid has the “ten essentials” printed on it, and I think this is especially great for a kids’ pack as they have a basic checklist easily printed that they can read through and double check.

Ten essentials printed on underside of lid, removable lid partially detached

All Day Hiking

A 40-liter pack is a very large daypack for a child, but on all-day adventures or times when they want to carry all the family gear, it could be used as a daypack. You’ll need to be careful about adding too much water if they are young as water weight adds up very quick.

Before using it on overnights this summer we have been using it as a daypack and around the house and yard to get used to the size of the pack. Just like breaking in a pair of hiking boots, it’s a good idea to get kids used to carrying a larger pack and get a feel for how much they can carry and for how long before you take your first trip out!

Fully loaded pack on the ninja line

A pack this size changes their center of gravity so the more they get used to it the better!

Appearance and Functionality

Pocket Usefulness

The water bottle pockets on the side are nice and deep but quite wide at the top. This could be a problem for things constantly falling out, but the side straps can be used to secure water bottles so that is a nice touch. Because of the wide tops, it will be easier to put water bottles back in or stash mittens and other small items quickly.

In my opinion, the top-lid pocket is not really removable unless using a rain cover, as you would expose the contents of the pack; and a rain cover is not included with this pack. REI packs I’ve owned in the past have had this same design, and I prefer the attached-lid style. Additionally, weight savings by removing the lid would be minimal.

Access to the interior of the pack is from the top only, there is no bottom zipper. For an adult pack I love having multiple access points but for a kids’ pack I like this design. A bottom zipper is a potential weak point if it’s not zipped up all the way, and there are enough outer pockets that accessing the interior of the pack mid-trip wouldn’t be necessary.

The hip belt pockets were one of my son’s favorite things about this pack, he speculated for quite some time about all the things he would put in them!

Fit and Comfort

The straps and back panel are very padded. This will be very nice for older kids carrying heavier pack weights, providing cushioning for heavier loads. For my child at the very lower end of the pack stats, it’s a bit much and makes getting a good fit harder than packs with more minimal strap and back padding.

What Does it Hold?

The pack can hold a ton of stuff, for the average 6/7/8 year old, it’s going to be tough to fill it without going over weight, so take care to put lighter things in the child’s pack (sleeping bag, extra clothes, snacks)!

Here it’s packed with things my 6.5 year old will be carrying when we use it for backpacking. He’s used to carrying a heavy pack but for longer trips this may be too much for him.

I usually have him carry only a small amount of water, and I carry most of the water and give him refills. However, older kids will be able to utilize the hydration compatibility and carry up to 3L of water.

Contents of the pack for just under 9 pounds total weight

Because of the weight of the pack, the items shown above (synthetic sleeping bag, wool socks, full change of wool clothes, hat, down vest, rain mittens, wool mittens, water and jerky) weigh in at around 6 pounds, making for a pack just under 9 pounds (which is 20% of my 6.5yo’s body weight).

Kids shouldn’t carry packs heavier than 10-20% of their body weight, so every ounce the pack weighs counts!

The Bottom Line

What we Love

The REI Tarn 40 is a wonderful option for a backpacking pack for children. It’s extremely well made and durable, the high denier ripstop nylon will challenge even the roughest handler to put a blemish on the pack.

This pack has lots of features that kids can get excited about! Especially pockets; the pockets are well placed and easy to open, and dual hip pockets is a very nice touch.

What we aren’t so crazy about

This pack is going to shine more in the slightly older age range, probably starting around age 8 or so. It does technically fit my 6.5 year old, but it’s not as comfortable for him as it would be for an older child with a longer torso. While REI suggests it for torso lengths 12-16″, I’d say 13″ and up as my son’s torso is about 12.25″.

In my opinion, backpacking packs should come with a rain cover, and ideally a separate pocket underneath to stow it. A rain cover for the pack is available separately, it retails for $26.95. While I think it should come with and be integrated into the pack, I do like that the rain covers come in bright colors and buying it separately gives us the choice, so we will use the yellow or orange for extra visibility (it also comes in gray).

Where to buy

The REI Tarn 40 and entire line of Tarn packs is available at REI.

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