The REI Co-op Magma 30 ($349) is a fantastic option for weight-conscious backpackers on a budget, offering an impressive warmth-to-weight ratio at a mid-range price. Few other bags at this price point are as lightweight and packable, making the Magma 30 an excellent companion for long, demanding trips. It also comes in a wide range of sizes, accommodating various body types for a better overall fit. While you do sacrifice some features and comfort with its function-first design, the Magma 30 remains a strong choice for practical backpackers looking for performance at a great value.
Warmth / Weight
Comfort
Features
Durability
Water Resistance
Sustainability
Temp Rating
34/24°F (ISO Comfort/Limit)
Weight
1 lb. 8.4 oz.
Fill
12.7 oz. of 850-fill down
Shell
15D nylon
Shoulder/Hip Girth
62.5/54 in.
Packed Volume
7.5L
Other Temps
15F
Pros
Cons
REI Co-op Magma 30
For this season's top models, see our guide to the Best Backpacking Sleeping Bags.
For its price, the REI Co-op Magma 30 has a surprisingly good warmth-to-weight ratio, ranking it at the top of our list for value-seekers still aiming to minimize pack size and weight. It accomplishes this feat with 850-fill-power down—a lofty down we typically see in more premium sleeping bags—in addition to a thin 15-denier shell fabric and a trimmed-down feature set. These design points put the Magma 30 in the same playing field as more expensive bags like the Therm-a-Rest Parsec 20 ($470) and Sea to Summit Spark 15 ($549)—but for up to $200 less.
The best way to understand this is by looking closely at the numbers: The REI Co-op Magma 30 has a comfort rating of 34 degrees Fahrenheit and a limit rating of 24 degrees, while the Parsec 20 has a comfort rating of 29 and a lower limit of 18. To reach this temperature rating, the Magma 30 packs in 12.7 ounces of 850-fill-power down for a final weight of 1 pound 8.4 ounces. On the other hand, the Parsec is heavier at 1 pound 13 ounces but uses 1 pound 1 ounce of 900-fill-power down. Without getting too deep into the details, it’s safe to say that the bags are fairly close in warmth for weight, with the Magma perhaps slightly edging out the Parsec due to its loftier down.
Looking at the Nemo Riff 30 ($360) provides a better contrast: The Riff 30 isn’t quite as warm as the Magma 30, with a comfort rating of 39 and a lower limit of 29, yet it weighs over 5.5 ounces more at 1 pound 14 ounces. Right off the bat, you can see that it’s less efficient in terms of warmth-to-weight. Checking out the Riff’s fill weight confirms this: It only has 10 ounces of 800-fill-power down, compared to the Magma’s 12.7 ounces of 850-fill-power down. All told, the Magma 30 doesn’t offer the same level of thermal efficiency as heavy-hitters like the Feathered Friends Swallow UL or Sea to Summit Spark, but it’s not far behind and offers considerable savings, making it a suitable choice for all but the most militant ounce counters.
For my purposes—multi-day backpacking trips with a 55-liter backpacking pack that can handle up to about 35 pounds—I found the Magma 30’s weight and packed size to be perfectly sufficient. REI includes a stuff sack, but you’ll likely want to replace it with a compression sack to achieve a smaller packed size. And I can confirm that the Magma’s stated temperature rating is accurate: I’ve spent multiple nights in the backpacking sleeping bag in temperatures hovering just above freezing and felt on the edge of its comfort range. I wouldn’t want to push it into below-freezing temps.
The Magma scores above average for comfort and is a wonderfully cozy place to call home for the night for all but the most princess-in-the-pea sleepers. The bag features a silky 15-denier fabric along with an insulated yoke that hangs around the neck to fill in gaps of dead air space. Unfortunately, this yoke isn’t as foolproof or cozy as a draft collar and dangles awkwardly when the bag isn’t zipped up. I’d much prefer an integrated draft collar, which REI likely omitted for weight and cost savings.
I found the REI Co-op Magma 30 to strike a nice balance between roominess and weight savings, and the good news is that it’s offered in nine unisex sizes—so if you want a wider or longer silhouette, you can find one. The unique zipper path adds to the bag’s comfort, wrapping from the side to the front, which makes it easier to zip and unzip. Too often, I go to unzip my sleeping bag only to realize I’m lying on top of the zipper, but this happens far less often with the Magma’s thoughtful design.
REI kept features to a minimum with the Magma 30 to keep weight low. You get an insulated yoke at the neck instead of a draft collar, which helps minimize drafts but feels like an awkward afterthought in design. The bag also includes an interior stash pocket that fits a phone or headlamp, though its integrated flap makes it somewhat difficult to retrieve items in the middle of the night. Finally, the Magma’s zipper is very well executed: it’s a two-way design with a snag-free pull at the top—something I think every sleeping bag should have.
The Magma 30 falls on the more delicate end of the down sleeping bag spectrum given its thin 15-denier ripstop nylon shell. Thankfully, REI incorporated an anti-snag zipper pull to reduce catching when zipping and unzipping the bag. Durability isn’t a strong important factor in my sleeping bag decision-making, as I most often transition my sleeping bag straight from a stuff sack into a backpacking tent. That said, on cold mornings and evenings in Washington’s Enchantments, I wrapped myself in the Magma while making coffee or drinking tea, and the bag held up well to the exposure. Unless you’re particularly hard on your gear or frequently sleep en plein air (without a tent), the REI Co-op Magma 30 should have solid longevity.
A wet backpacking sleeping bag can turn an otherwise great backpacking trip into a miserable experience, especially if it's packing down insulation. Thankfully, the REI Co-op Magma 30 includes thoughtful design features to help mitigate moisture concerns. The Magma’s shell and lining are treated with a nonfluorinated durable water repellent (DWR) finish, allowing light moisture to bead up and roll off rather than soaking in. And if some dampness sneaks through, the bag’s water-resistant goose down provides an added layer of defense, which is important to helping the down maintain its loft and warmth. This level of water resistance is sufficient for dealing with light condensation or damp tent walls, but it should by no means be thought of as permission to get your bag wet. I recommend packing the Magma in a waterproof stuff sack and keeping it away from all moisture.
Select icon to view details:
Longevity
Choosing durable outdoor gear and keeping it in use for longer is one of the best ways to reduce environmental impact. Our proprietary longevity rating assesses factors like overall build quality, materials, fabric denier, component durability, and real-world performance. A green check indicates that we expect the product to be long-lasting relative to its peers, a yellow check mark indicates average longevity, and a red X indicates a product that may have a limited lifespan.
Responsible Down
The Responsible Down Standard (RDS), developed by Textile Exchange, is the leading certification for responsibly sourced down and uses third-party audits throughout the supply chain to verify animal welfare, responsible farming practices, and safe working conditions. Recycled down is another responsible choice that helps reduce demand for newly sourced down while keeping existing materials in circulation. A green check mark indicates a product uses responsibly sourced or recycled down, a yellow check mark indicates the brand sources responsible or recycled down for the majority of its products but does not specify it at the product level, and a red X indicates the product does not use responsibly sourced or recycled down.
PFAS-Free DWR
Durable water-repellent (DWR) finishes can contain PFAS (per- and polyfluoroalkyl substances). These highly persistent “forever chemicals” are used in outdoor gear for their strong resistance to water, oil, and heat, but are linked to environmental contamination and a range of health concerns. A green check mark indicates the product uses a PFAS-free DWR, while a red X means the DWR contains PFAS.
Recycled Materials
Recycled materials are prevalent in outdoor gear, with nylon, polyester, wool, and down among the most common, but the composition varies widely. A green check mark indicates the product is made with a substantial amount of recycled materials (100% recycled or the core fabric that makes up most of the product is recycled), a yellow check means it contains a moderate to small amount of recycled materials, while a red X means there are no recycled materials in the product.
Bluesign Approved
Bluesign Technologies, based in Switzerland, operates a third-party textile management system that ensures materials are manufactured to strict environmental, chemical, and worker safety standards. A green check mark indicates a product is either a Bluesign Product (contains at least 90% Bluesign-approved fabrics and 20-30% Bluesign-approved accessories) or features a significant amount of Bluesign-approved materials. A yellow check mark means it uses some Bluesign-approved materials but less than the aforementioned category, and a red X means there are no Bluesign-approved materials in the product.
Responsible Manufacturing
This criterion evaluates a brand’s commitment to fair wages, safe working conditions, and reducing environmental impact through certifications and programs like Fair Trade Certified, Fair Wear Foundation, Worldwide Responsible Accredited Production (WRAP), and the Fair Labor Association, while also recognizing brands that manufacture primarily in the U.S. or Europe under strict labor and environmental regulations. A green check mark indicates a brand meets our responsible manufacturing criteria, while a red X means it does not.
Recycled and/or Reduced Packaging
Packaging can add significant waste to outdoor gear purchases, so many brands work to reduce its impact by using recycled materials, incorporating Forest Stewardship Council-certified paper products, and minimizing plastic and paper use. A green check mark indicates a brand uses recycled or reduced materials across all of its packaging, a yellow check indicates moderate or limited use of recycled or reduced packaging, and a red X indicates the brand does not make either of these efforts.
Repair Services
Repair services extend the lifespan of outdoor gear and reduce overall consumption, though programs vary widely. Some brands offer comprehensive repairs for a range of issues, while others provide limited or no repair support. A green check mark indicates a robust repair program, a yellow check mark indicates limited repair services, and a red X indicates the brand does not offer repair services.
Resale and/or Recycling Services
Resale and recycling programs help keep outdoor gear in circulation longer and out of landfills, ranging from trade-in resale platforms that offer store credit to take-back initiatives that recycle products at the end of their usable life. A green check mark indicates a brand offers both resale and recycling programs, a yellow check mark indicates it offers one or the two, and a red X indicates it offers neither.
Carbon Footprint Tracking
This criterion evaluates whether a brand measures, reports, and works to reduce its greenhouse gas emissions using established frameworks such as the Higg Index, Greenhouse Gas Protocol, or The Change Climate Project. A green check mark indicates a brand publicly reports greenhouse gas emissions data, sets clearly defined reduction targets, and uses established tracking frameworks such as Higg or The Change Climate Project. A yellow check mark indicates the brand tracks emissions and outlines reduction goals but provides limited data, lacks science-based verification, or does not clearly report progress. A red X indicates the brand does not appear to track greenhouse gas emissions or provides so little information that its efforts cannot be verified.
Annual Impact Report
Annual impact reports provide transparency and accountability by outlining a brand’s sustainability efforts across areas such as material sourcing, greenhouse gas emissions, waste, water use, supply chains, and packaging. A green check mark indicates a brand publishes a detailed, brand-specific impact report that closely aligns with our sustainability criteria and leaves little room for ambiguity. A yellow check indicates a brand provides some relevant sustainability reporting but lacks detail in key areas or is covered only briefly within a parent company report. A red X indicates a brand does not regularly publish an impact report.
One of the key ways the REI Co-op Magma 30 differentiates itself from the rest of the market is its sizing. The bag has a traditional mummy shape and is available in nine different sizes, combining three lengths (short: 5’5”, medium: 5’11”, long: 6’5”) and three widths. I’m 5’6” and 135 pounds and tested the medium bag in its mid-range width. The fit felt notably tapered, especially around the hips and knees—for comparison, it measures 62.5 inches at the shoulders and 54 inches at the hips, whereas the Parsec has a slightly roomier 62- and 57-inch girth. That said, I’m always willing to accept a snugger fit for weight and space savings. If you prefer more room to toss and turn or sleep on your side, consider the wide versions.
Therm-a-Rest Parsec 20 ($470): A Level-Up
Despite the “20” in its name, the Therm-a-Rest Parsec 20 is a relatively close competitor to the Magma 30, with a comfort rating of 29 degrees compared to the Magma’s 34. The Parsec is about 4.5 ounces heavier and packs in over 4 ounces more down, with a slightly higher fill power (900 vs. 850). Where the Parsec really earns its higher price point is in its feature set and comfort: it offers a true draft collar (whereas the Magma’s yoke is underwhelming), an external pocket with a secure zipper, and a “Toe-asis” footbox that allows you to cozy up your feet on cold nights. Additionally, its slightly thicker 20-denier fabric feels noticeably softer and silkier. The Parsec’s overall dimensions are a bit roomier as well, though you can achieve a similar fit by opting for the wide-sized Magma. All told, the Parsec delivers a more premium feel and slightly more warmth than the Magma, but you’ll have to decide if that’s worth the additional investment.
Mountain Hardwear Bishop Pass 30 ($315): Solid Value & Durability
If the Magma 30’s price point is its most appealing trait, it’s worth looking at a cheaper sleeping bag like the Mountain Hardwear Bishop Pass 30. At this price point, some real compromises emerge in terms of warmth-to-weight. The Bishop Pass 30 isn’t as warm as the Magma 30, with a comfort rating of 40 degrees, and it’s about 4 ounces heavier overall at 1 pound 12.6 ounces. This is due to budget-minded choices such as a less-efficient 650-fill-power down and a thicker 30-denier shell. The Bishop Pass also lacks a draft collar or insulated yoke, though it does have a lofty baffle that frames the face to help trap warmth. If you’re looking to save, it’s a durable bag with decent comfort, but we don’t recommend it for those who prioritize keeping weight and bulk to a minimum. For more, read our Mountain Hardwear Bishop Pass 30 review.
REI brings premium sleeping bag design to the masses with Magma, an 850-fill power model that boasts an extremely reasonable price point. Throw in a plethora of size options—the most of any model we’ve seen from a major brand—and there is a lot to like about this bag.
Warmth / Weight
Comfort
Features
Durability
Water Resistance
Sustainability
A three-season bag that undercuts much of the competition on price, the Parsec offers a competitive warmth-to-weight ratio, above-average durability, and a handful of thoughtful quality-of-life features. Roomy dimensions and the lack of a short size make it a less ideal fit for smaller users.
Warmth / Weight
Comfort
Features
Durability
Water Resistance
Sustainability
Despite its no-frills mummy design, there’s much to like about the reasonably priced Bishop Pass. It’s not supremely light or packable, but it’s a good value buy for hikers who sleep in relatively balmy three-season temps.
Warmth / Weight
Comfort
Features
Durability
Water Resistance
Sustainability
The REI Co-op Magma 30 is an excellent choice for backpackers who prioritize a strong warmth-to-weight ratio at a reasonable price. With 850-fill-power down, a trimmed-down feature set, and a competitive weight, it performs alongside more premium options while maintaining a budget-friendly edge. It’s also offered in nine unisex sizes, so finding the right fit shouldn’t be an issue. However, the Magma lacks some comfort features found in modern sleeping bags—including a draft collar, venting, and a semi-rectangular shape—making it less ideal for picky sleepers or those needing a wider temperature range. But if you typically camp in above-freezing temperatures and want a lightweight, efficient sleeping bag, the Magma 30 is a high-value choice that punches above its price point.
leave home prepared
Gear Guide
Best Backpacking Sleeping Pads of 2026Gear Guide
Best Backpacking Tents of 2026Gear Guide
Best Backpacking Backpacks of 2026Gear Guide
Best Trekking Poles of 2026curated for you