REI Magma 15 sleeping bag camping outside

REI Magma 15-Degree Sleeping Bag Review: Simple, Warm Slumber

Plenty of warmth and intuitive design make the REI Magma 15 sleeping bag a simple, solid three-season option.

I like to think of backpackers in two categories: those who prefer comfort while hiking and those who prefer comfort in camp. For the most part, I find myself in the first group, angling for lightweight gear, simple meals, few amenities, and no spare underwear.

But sleeping bags are where I make an exception.

I figure if I’m going to spend roughly one-third of any given backcountry day in a sleeping bag, I shouldn’t skimp on warmth or comfort. Plus, a good night’s sleep makes a big difference the next day, allowing you to do more.

REI Magma 15 sleeping bag

So I’m particular about the shape, fill, weight, and durability of sleeping bags. When I research new ones, I dig into every fine detail except the color. I’m admittedly color agnostic.

Naturally, when I received an opportunity to test REI’s upcoming sleeping bag, the Magma 15 (available in men’s and women’s), I jumped at it.

In a saturated market like sleeping bags, it’s the fine details that make a product stand out. And what better way to learn about the nitty-gritty than a late-season backpacking trip filled with dirt, sand, water, and cool nights? So I hopped on a plane and headed for Aravaipa Canyon in Arizona.

REI Magma 15 Sleeping Bag Review

My first impression of the Magma 15 was its weight — or lack thereof. For a three-season sleeping bag, the weight was shocking at less than 2 pounds. Thanks to the lightweight construction, a fitted silhouette, and premium goose down, REI’s Magma sleeping bag delivers a surprisingly good warmth-to-weight ratio.

While REI designed the Magma for use in spring, summer, and fall, some might also find it useful on winter trips. The sleeping bag has water-resistant fill and a Pertex shell, permitting more nights camping without a rainfly and more comfortable nights at high-alpine bivies. And, in general, more nights in a dry sleeping bag is an obvious plus.

REI Magma 15 sleeping bag foot box

I was pleasantly surprised by how much knee and foot space the sleeping bag provides, especially considering it has a fitted cut that helps shave the overall weight.

It was also nice to see a finely baffled footbox that’ll keep toes warmer, paired with variable baffles across the entire bag. This design aims to equalize the down fill and keep the warmth throughout the bag more even. And for those looking for something slightly lighter for summer hiking, the Magma also comes in 30-degree and trail quilt options.

REI Magma 15 sleeping bag anti-snag zipper

The zipper on the Magma is large and includes both a cover and anti-snag strip to help mitigate most zipper issues that plague some bags. Meanwhile, the hood of the mummy bag has a shape that’s just big enough for a small pillow. Plus, it’s adjustable from the inside of the bag — a nice, if small, touch.

REI Magma 15 sleeping bag hood

An insulated yoke fills the weird gap near your neck and shoulders, which helps prevent heat loss. And a draft tube along the zipper further insulates body heat.

REI Magma Sleeping Bag Specs

In all, there are very few cons to point to with the Magma. It’s comfortable, light, and thoughtfully designed. After a few nights of use in canyon country, I quickly started to feel at home. Check out the specs below:

REI Magma 15 Sleeping Bag

  • MSRP: $369 (regular) / $389 (long)
  • Fit: Fitted (men’s / women’s)
  • Temperature rating: 15 F (-9.4 C)
  • ISO comfort rating: 28 F (-2 C)
  • ISO extreme rating: 17 F (-27 C)
  • Shape: Mummy
  • Weight
    • Men’s: 1 lb. 12.2 oz. (regular) / 1 lb. 14.6 oz. (long)
    • Women’s: 2 lbs. 4 oz. (regular) / 2 lbs. 6 oz. (long)
  • Fits up to (length)
    • Men’s: 72″ (regular) / 78″ (long)
    • Women’s: 66″ (regular) / 72″ (long)
  • Shoulder girth: 60″
  • Hip girth: 57″
  • Shell: Pertex 15-denier ripstop nylon (bluesign-approved)
  • Lining: 15-denier ripstop nylon (bluesign-approved)
  • Fill: 850-fill-power grey goose down
  • Fill weight: 15.9 oz. (regular size)
  • Water resistance: Yes
  • Compressed size
    • Men’s: 5.2L (regular) / 5.7L (long)
    • Women’s: 7.3L (regular) / 10L (long)
  • Zipper location: Left (men’s) / Right (women’s)
  • Stuff sack size: 7.5″ (diameter) x 15″ (height)

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