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REI Co-op Magma 30: The Ultimate Lightweight Sleeping Bag for Three-Season Adventures

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Highlights of the REI Co-op Magma 30 Sleeping Bag: 

  • Exceptional Warmth-to-Weight Ratio: At just 1 pound 4 ounces, the Magma 30 provides impressive warmth with its 850-fill-power goose down, perfect for ultralight backpacking.
  • Durable and Water-Resistant: Made with Pertex Quantum shell fabric, this sleeping bag offers durability and protection against moisture, ensuring longevity and performance in various conditions.
  • Ethically Sourced Materials: The Responsible Down Standard (RDS) certified down ensures ethical treatment of animals and traceability, aligning with sustainable and humane practices.

The REI Co-op Magma 30 sleeping bag, priced at $379.00 and available in the sleek Thunder Blue colorway, is a standout product in the world of ultralight backpacking gear. With its impressive warmth-to-weight ratio, premium materials, and thoughtful design, the Magma 30 aims to be a go-to choice for backpackers and campers looking to maximize comfort while minimizing pack weight. In this review, we will delve into the various aspects of this sleeping bag, including its design, performance, materials, and overall value.

Magma 30. Photo: REI Co-op

Design and Features

The REI Co-op Magma 30 is designed with a clear focus on balancing weight, warmth, and packability. One of the first things you’ll notice about the Magma 30 is its sleek, minimalist aesthetic. The Thunder Blue colorway is both modern and subtle, appealing to those who prefer a classic look without compromising on style.

Weight and Packability

At just 1 pound 4 ounces (regular size), the Magma 30 is exceptionally lightweight, making it an ideal choice for ultralight backpackers. The included stuff sack allows the bag to compress down to a compact size, easily fitting into the bottom of a backpack. This level of packability is achieved without sacrificing warmth or comfort, thanks to the high-quality materials and construction.

Temperature Rating

The Magma 30 is rated for comfort at 39°F and a lower limit of 30°F, making it suitable for three-season use. This temperature rating is achieved through a combination of high-quality down insulation and efficient design. The bag’s mummy shape and well-fitted hood help to trap body heat, ensuring a warm and cozy night’s sleep even in cooler conditions.

Zipper and Draft Collar

The bag features a full-length, anti-snag YKK zipper that runs smoothly and is easy to operate, even in the dark. A draft collar and draft tube along the zipper help to seal in warmth and prevent cold air from entering the bag. These features are particularly important in cooler temperatures, as they enhance the bag’s overall thermal efficiency.

Materials and Construction

The REI Co-op Magma 30 utilizes premium materials to ensure durability, comfort, and insulation efficiency.

Down Insulation

The Magma 30 is filled with 850-fill-power goose down, which is both lightweight and highly compressible. This high-quality down provides excellent loft and warmth while maintaining a minimal weight. Additionally, the down is responsibly sourced and certified to the Responsible Down Standard (RDS), ensuring ethical treatment of animals and traceability throughout the supply chain.

Shell and Lining Fabrics

The outer shell of the Magma 30 is made from Pertex Quantum, a lightweight, durable, and highly water-resistant fabric. This material helps to protect the down insulation from moisture, maintaining its loft and insulating properties even in damp conditions. The inner lining is made from a soft, breathable nylon fabric that feels comfortable against the skin, enhancing overall sleep comfort.

Comfort and Fit

The mummy shape of the Magma 30 is designed to maximize thermal efficiency while providing enough room to move comfortably. The bag tapers from the shoulders to the footbox, reducing dead space and ensuring that body heat is efficiently retained.

Hood Design

The hood of the Magma 30 is well-contoured and adjustable, providing a snug fit around the head and neck. This design helps to minimize heat loss from the head, which is crucial in maintaining overall body warmth. The hood also features a small stash pocket, perfect for storing small items like a headlamp or phone.


The trapezoidal footbox is designed to provide ample space for your feet, allowing for natural movement and reducing the likelihood of cold spots. This design is particularly beneficial for side sleepers or those who move around during the night.

Performance in the Field

In practical use, the REI Co-op Magma 30 performs admirably in a variety of conditions. Its lightweight and compact design make it easy to carry on long hikes, while its impressive warmth ensures a comfortable night’s sleep in temperatures down to the mid-30s.


During field tests, the Magma 30 has proven to be warm and cozy, even in temperatures approaching its lower limit. The combination of high-fill-power down, efficient design, and well-placed draft collars and tubes all contribute to its excellent thermal performance.


Despite its warmth, the Magma 30 also offers good breathability, preventing overheating and moisture buildup inside the bag. This balance of warmth and breathability makes it suitable for a range of conditions, from chilly nights to milder temperatures.


The Pertex Quantum shell fabric is both lightweight and durable, standing up well to the rigors of outdoor use. The high-quality down insulation maintains its loft and insulating properties over time, provided it is properly cared for.

Value for Money

At $379.00, the REI Co-op Magma 30 is a significant investment. However, considering the premium materials, excellent design, and high performance, it offers good value for money. The bag’s durability and versatility make it a long-term investment that can serve well over multiple seasons and various types of adventures.

Pros and Cons

  • Lightweight and Compact: At just 1 pound 4 ounces, the Magma 30 is easy to carry and pack, making it ideal for ultralight backpacking.
  • High-Quality Down: The 850-fill-power goose down offers excellent warmth-to-weight ratio and compressibility.
  • Comfortable Design: The mummy shape, well-fitted hood, and spacious footbox provide a cozy and efficient sleeping experience.
  • Durable Materials: The Pertex Quantum shell is lightweight, durable, and water-resistant, protecting the down insulation effectively.
  • Ethical Sourcing: The RDS certification ensures that the down is responsibly sourced, aligning with ethical and sustainable practices.
  • Price: At $379.00, the Magma 30 is a significant investment, though its performance and durability justify the cost for serious backpackers.
  • Temperature Limit: While suitable for three-season use, the Magma 30 may not provide enough warmth for winter camping or temperatures significantly below its 30°F lower limit.


The REI Co-op Magma 30 sleeping bag is a top-tier choice for backpackers and campers who prioritize lightweight, high-performance gear. Its excellent warmth-to-weight ratio, premium materials, and thoughtful design make it a reliable and comfortable option for three-season use. While the price point is higher than some alternatives, the investment is justified by the bag’s durability, ethical sourcing, and overall performance.

Whether you’re planning a multi-day backpacking trip or looking for a reliable sleeping bag for car camping adventures, the Magma 30 is a versatile and dependable option that delivers on its promises. Its combination of warmth, weight, and packability sets it apart in the crowded field of backpacking sleeping bags, making it a standout product that is well worth considering for your next adventure.

Get the REI Co-op Magma 30 sleeping bag

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