REI Co-op
Magma 10
Best lightweight sleeping bag for cold weather backpackers seeking premium value.
This lightweight sleeping bag offers an impressive warmth-to-weight ratio, making it an excellent choice for backcountry adventurers who prioritize packability. It utilizes high-quality down insulation and a durable, weather-resistant shell to handle cold conditions effectively. While it lacks some of the more robust features found in heavier, more expensive alternatives, it provides a streamlined design that excels in alpine environments. The snag-free zipper and adjustable hood ensure ease of use, while the various fit options allow for a personalized balance between comfort and weight savings.
$56.00
More Magma Options
Owner Satisfaction
4.6
/ 5
Category Rank
307
/ 2020
#307 in Sleeping Bags
Price vs Category Average
-67%
Below average
Who it's for
- Ultralight backpackers prioritizing pack weight and thermal efficiency
- Eco-conscious campers seeking ethically sourced high-performance gear
- Side and back sleepers who need efficient heat retention
Who should skip it
- Restless sleepers or larger individuals who feel claustrophobic in tight bags
- Rough-use campers who frequently sleep directly on the ground
- Budget-conscious hikers who only camp during the warm summer months
Performance breakdown
Warmth-to-weight ratio
High-loft down provides exceptional insulation without the typical bulk.
Packability
Compresses down to a remarkably small size for easy pack integration.
Draft protection
The contoured hood and draft collar seal out cold air effectively.
Zipper performance
Anti-snag design works smoothly, though requires care with lightweight fabrics.
Interior comfort
Roomy enough for side sleepers without sacrificing thermal efficiency.
Moisture resistance
Water-repellent down treatment helps maintain loft in damp conditions.
Know before you buy
The Magma 10 is EN-rated with a comfort rating of 22°F and a lower limit of 10°F. This means most sleepers will feel comfortable down to 22°F, while the 10°F rating is the point where you can survive the night without hypothermia, provided you are wearing base layers and using a quality sleeping pad.
Yes, the Magma 10 features a contoured, mummy-style cut that is surprisingly roomy in the shoulders and hips. While it is still a mummy bag, the design allows for enough movement to shift positions comfortably without feeling restricted.
The bag uses 850-fill-power goose down that has been treated with a water-repellent finish. While this helps the down resist moisture and dry faster than untreated down, it is not waterproof, so you should still use a waterproof stuff sack and keep it dry inside your pack.
No, the Magma 10 is designed as a standalone mummy bag and does not feature a zipper system that allows it to be mated or zipped together with other sleeping bags.
To get the most out of the Magma 10's temperature rating, you need an insulated sleeping pad with a high R-value, ideally 4.0 or higher. Since the insulation on the bottom of the bag is compressed by your body weight, the pad is your primary defense against cold ground.
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