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REI Magma Sleeping Bag Review

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If you’re looking for one sleeping bag to do it all, it’s tough to beat the value of the REI Magma 15 and Magma 30. The Magma is constructed with high-quality materials, has an excellent warmth-to-weight ratio, will keep you comfortable into sub-freezing temperatures, and comes at a surprisingly reasonable price in the world of premium down sleeping bags. For warm summer nights, the Magma will likely be overkill (we like quilts for those trips), but when temperatures drop, you’ll be happy to have the toasty warmth of the Magma.

Quick Specs

REI Magma 15 & 30

Weight: 2 lb. 3.6 oz. / 1 lb. 8.4 oz. (medium)

Temperature Rating: EN lower limit 9°F / 24°F

Comfort Rating: EN comfort 21°F / 34°F

Down Fill: Water-resistant 850 fill goose down

Dimensions: 71 in. long x 62.5 in. shoulder girth

Packed Size: 7.8 x 16.5 in. / 7 x 15 in.

Sizes: short narrow, short, short wide; medium narrow, medium, medium wide; long narrow, long, long wide


  • Lightweight
  • Very good value
  • No snag, full-length zipper with draft tubes to contain warmth
  • Good warmth-to-weight ratio
  • Comfortable ergonomic hood and footbox design
  • Neck collar helps contain body heat
  • Made with water-resistant down


  • A bit heavy, bulky, and warm for summer use
  • More pricy than heavy/bulky budget options
  • No small stash pocket for earplugs or electronics

REI Magma Specs


For the quality of materials and warmth-to-weight ratio, we think the REI Magma is one of the best value sleeping bags on the market. REI is able to keep prices down by selling mass production products directly to the consumer with no middleman. The Magma still isn’t cheap, but it’s a great deal when compared to sleeping bags of a similar quality. Also, down products can last for decades if taken care of properly.


Weighing 1 lb. 8.4 ounces for the Magma 30 medium, this bag has a very good warmth-to-weight ratio among sleeping bags and will keep you comfortable into sub-freezing temperatures. If you primarily backpack in warm summer weather, the weight and temperature rating of this bag may be a bit much (we like quilts for those trips), But if you’re looking for a bag that can do it all and will rarely feel too heavy or bulky, the Magma is an excellent fit.


The Magma has an EN “lower limit” of 10°F for the men’s version and 3°F for the women’s version, but don’t use those as your main guide. We find that EN “comfort” ratings tend to be a much more realistic measurement for the lowest temperatures you should plan to encounter. The EN comfort rating for the Magma 15 is 21°F, and 34°F for the Magma 30. This means the Magma will keep you warm enough into sub-freezing temperatures, which is really solid, and will allow you to use the Magma on a wide variety trips, even really chilly ones. Just don’t expect to be kept warm down to the lower limit ratings (9°F or 24°F), because you’ll be in for a very chilly night.

Down fill

The 850 fill power goose down in the Magma strikes a good balance between weight and cost. The water-resistant treatment of the down will help keep your bag from soaking through if it gets wet and will help it dry out quicker too. That said, we always recommend heavily protecting your sleeping bag to avoid contact with water altogether.We use a 13L S2S eVAC Dry Sack dry bag when we pack the Magma in our backpacks and rely on trusty waterproof shelters to keep it dry at night.


For its warmth rating, the Magma compresses down very small into an included stuff sack with packed dimensions of 7.5 x 15 inches (photos in the gallery above). If you’re looking for the smallest possible pack size, you could pair the Magma with a compression stuff sack and cinch it down even smaller. Some of the leading competition might pack a tad smaller, but the Magma is still very good in this arena.


The interior fabric on the Magma is soft and comfortable against the skin. The exterior fabric is fairly thin in order to keep weight to a minimum. We think the Magma is durable enough to withstand the rigors of the trail, but like all lightweight backpacking gear, you’ll want to treat it with care. If you do develop any small rips or tears, Tenacious Tape will work well to fix them quickly.

Size Options

The REI Magma is offered in 15 and 30-degree versions in a wide array of sizes. Getting the right size reduces the dead space that your body has to heat so finding the perfect fit among the short, short narrow, short wide, medium, medium narrow, medium wide, long, long narrow, and long wide options is a game changer.


The ergonomic footbox is roomy, comfortable, and has plenty of down to keep your feet warm. 


We love how easily the no-snag zipper slides on the Magma and consider this a big win compared to the competition. The zipper runs the full length of the bag and allows you the option to open the Magma up and drape it over you on warm nights. There’s a draft tube (down filled tube) that runs the full length of the zipper to help keep heat in and minimize cold spots.

Hood & Draft Collar

The ergonomic hood fits the head very well and has two cinch cords to tighten it close to your face on cold nights. The hood section has a substantial amount of down, ensuring your head will stay toasty warm too.

Bottom Line

If you’re looking for a high-quality down sleeping bag to cover a wide range of backcountry trips, the REI Magma is an excellent choice. The Magma will keep you warm into sub-freezing temperatures without weighing down your pack or stretching your wallet. While not cheap, the REI Magma has a very reasonable price tag for a sleeping bag with it’s specs. In fact, we think the REI Magma may just be the best value sleeping bag on the market.