REI Magma Down Sleeping Bag review

REI Magma Sleeping Bag: A Top Value In Down

Filed under: Sleeping Bags/Pads  Women 

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REI upgrades its classic sleeping bag with one of the best warmth-to-weight-to-price bags on the market today.

REI Magma Down Sleeping Bag review

Looking for a single sleeping bag to cover most of your backcountry adventures? A 20-degree bag brings the most bang for your seasonal buck. Pair it with an appropriate pad, and a good sleeping bag can keep you snoozing well into the shoulder seasons.

But not all bags are created equal. Higher quality fill can plump a bag at a fraction of the weight, but it’s expensive to source and can rapidly push up the price. Thus, there’s often a trade-off between insulation performance and price.

Enter REI’s Magma series. This just-launched line of men’s and women’s 850-fill bag costs nearly $100 less than their competitors. Do we have your attention? Read on for more.

REI Magma: Overview

REI Magma Down Sleeping Bag review

Completely redesigned from the ground up in 2017, REI’s Magma 17 retains all that was good in the first run (the mummy fit, solid draft collar, competitive price), but it just keeps getting better with each sequential release.

This year the Magma was overhauled to give a little extra knee and extra foot room for a less claustrophobic feel. Plus it upgraded to 850-fill, DWR-treated down, which helped drop the weight. All the while, REI reduced the price.

REI Magma 17 Sleeping Bag: Womens

  • Weight: 2 lbs., 4 oz. (regular) / 2 lbs., 6 oz. (long)
  • Shell: Downproof Pertex
  • Liner: 15-denier Ripstop Nylon
  • Insulation: 850-fill, DWR-treated goose down
  • RDS certified down
  • Fit: Mummy
  • Rating: Comfort: 17˚ F / Lower limit: 3˚ F
  • Compressed volume: 7.3 L (regular) / 7.9 L (long)
  • Zipper: Right
  • More Info/Buy now: $349 (regular) / $369 (long)

REI Magma 10 Sleeping Bag: Mens

  • Weight: 1 lb. 14 oz. (regular) / 2 lbs. (long)
  • Shell: 15-denier ripstop nylon
  • Liner: 15-denier Ripstop Nylon
  • Insulation: 850-fill, DWR-treated goose down
  • RDS certified down
  • Fit: Mummy
  • Rating: Comfort: 22˚ F / Lower limit: 10˚ F
  • Compressed volume: 7.3 L (regular) / 7.9 L (long)
  • Zipper: Right
  • More Info/Buy now: $349 (regular) / $369 (long)

Review: Magma 17 Women’s Sleeping Bag

GearJunkie tested the Women’s Magma over a series of nights in a remote Idaho cargo container-turn-cabin, with outside temperatures in the teens, and inside temperatures dipping down into the 20s.

The double zipper runs top to bottom and zips around the chin like a parka. It’s easy to close from the inside and feels roomy for a mummy bag. There’s enough room to move your legs during the night. Plus, the bag can unzip from the bottom to vent trapped body heat.

The Magma 17 is overfilled with 850-fill down stuffed inside a Pertex Quantum shell, bringing the bag’s comfort level to 17˚F. The 17˚ F comfort rating seems true to spec and is a nice addition. Women tend to cool quicker than men and the extra down addresses this. (Note, the men’s Magma is rated to a lower limit of 10˚ F. The Women’s lower limit is listed as 3˚ F. In short, the women’s bag is warmer than the men’s).

REI Magma Down Sleeping Bag review
The right side of the Women’s Magma seals shut with a nifty zipper that wraps cleanly around the front and is designed to snag less.

The updated hood is also exceptionally well-designed, cocooning around the face like a jacket hood. But there’s still enough room to stuff a pillow under the head for “just-like-home” comfort. The hood seals with a draft yoke that snugs under the chin to prevent heat from chimneying out.

REI Magma Down Sleeping Bag review

The bag comes with a mesh storage sack and nylon stuff sack. But experienced backpackers may want to buy an aftermarket compression sack. We highly recommend Sea-to-Summit’s compression sacks, available in eVent, Ultra-Sil, and Ultra-Sil Dry.


  • Better fit than its pedigree
  • Premium 850-fill water-resistant down
  • Responsible Down Standard-certified
  • Luxuriously soft
  • Reasonably priced (for an 850-fill bag)


  • Pricey, but it’s the highest quality down currently available at REI
  • Lacks double layer outer shell seen in prior Magma bag, potentially reducing moisture protection and affecting long-term durability

How It Stacks With The Competition.

REI chose 850-fill to compete against the premium third-party bags on its shelves. The 850-fill Nemo’s Sonic 15, for example, is rated for the upper 20s, weighs a few ounces more, but runs $430-$460 (roughly $100 more than the Magma).

Mountain Hardwear’s pièce de résistance, the 800-fill Phantom Flame 15, weighs in a smidge lighter (2 lbs., 1 oz. for the regular), but costs more than $500.

In fact, most of the quality bags at REI filled with 800-fill price out between $400-$475. That’s what makes the Magma 17 such a unique buy, not just at REI, but across the board.

We’ve not had the chance to test the men’s Magma 10 yet (this review covered the women’s model), but we suspect it will earn similarly high marks.

The Magma punches above its weight class with premium down, fantastic compression, and intelligently designed details. Better legroom, a snug hood, and a snag-free zipper are great features that make the Magma an intriguing option for those looking to cocoon for long backcountry nights.

tagged: firstlook review
Contributing Editor (and Gear Junkie Idaho Bureau Chief) Steve Graepel is allegedly a crook and a thief, conning his friends to steal away time from their families in pursuit of premeditated leisure, which typically involves a bike, a pack-raft, skis, running shoes, climbing rack, or all of the above.