The success of any adventure often comes down to having the right gear. Unfortunately, certain key pieces of gear, like sleeping bags, are often cumbersome. Fret not. In this article, we show you what makes a sleeping bag ultralight, what to look for when choosing one, and offer up our top picks for 2024. 

Whether you’re a seasoned adventurer or a newcomer to the trail, this guide will help you find the perfect ultralight sleeping bag to keep you warm and comfortable—without weighing you down.

What Makes a Sleeping Bag Ultralight?

Ultralight sleeping bags are designed to minimize weight without sacrificing functionality. This is what has made them so popular among today’s backpackers, thru-hikers, and anyone seeking to reduce their base weight.

Achieving this delicate balance lies in the choice of materials and construction techniques. Typically, ultralight sleeping bags feature high-fill power down insulation or advanced synthetic alternatives that offer excellent warmth-to-weight ratios. Goose and duck down are especially recognized for their unparalleled compressibility and thermal efficiency.

The outer shell and lining materials also play a role in reducing weight. These fabrics are treated with water-repellent coatings to protect the insulation from moisture, maintaining the bag’s performance in damp conditions. Other minimalistic features, such as reduced zipper lengths, help shave unnecessary ounces.

What to Look for in a Good Ultralight Sleeping Bag

Choosing the right ultralight sleeping bag is crucial for a comfortable night in the woods. When choosing your sleeping bag, keep these key factors in mind.

  • Weight-to-Warmth Ratio

This ratio determines how effectively a sleeping bag retains heat relative to its weight. A good ultralight sleeping bag should provide adequate warmth for the expected conditions, while keeping weight to an absolute minimum. Look for bags with high fill power (typically 800 or higher for down), as they offer superior warmth with less weight.

  • Insulation Type

Down is invaluable as an insulation for colder places as long as it remains dry. It provides the best weight-to-warmth ratio and compressibility, making it the preferred choice for ultralighters. If you find yourself overnighting in rainier or humid conditions however, synthetic insulation is more favourable because of its water-resistant and fast-drying properties, despite being slightly bulkier. If you want to know more about their differences, we have a down vs. synthetic guide available.

  • Shell Material and Durability

High-tenacity nylon or polyester fabrics are commonly used because they’re lightweight and durable. These materials are treated with a strong water repellent (DWR) coating to resist moisture and protect the insulation. Additionally, ripstop weaving makes the fabric resistant to tearing or prevents small rips from spreading further.

  • Packability and Compressibility

A good ultralight sleeping bag should compress easily into your pack, leaving room for other essentials. Needless to say, down bags excel in this area. Compression sacks come in handy to further minimize volume, but many ultralight purists eschew them altogether.

Our Top Picks for Ultralight Sleeping Bags

With these key factors in mind, let’s dive into our top picks for ultralight sleeping bags.

Weighing a mere 1 lb. 4 oz., the Therm-a-Rest Hyperion 20 °F/-6 °C Sleeping Bag sets a new standard for avid backpackers. Its featherlight weight doesn’t compromise warmth, thanks to the thermally efficient box baffles that ensure maximum loft and minimize cold spots.

This innovative design, paired with 900-fill Nikwax Hydrophobic Down, keeps the sleeping bag drier and maintains its loft significantly longer than untreated down, even in damp conditions.

Certified by the Responsible Down Standard, the Hyperion not only delivers top-notch performance but also adheres to ethical sourcing practices, making it a superior choice for eco-conscious adventurers.

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The NEMO Equipment Riff 15 °F/-9 °C Ultralight Sleeping Bag is a high performance option for three-season camping, weighing 2 lb. 7 oz. Featuring an innovative Ultralight Spoon shape, it offers ample space at the elbows and knees, making it perfect for side sleepers.

One of the Riff’s standout features is its next-gen Thermo Gill vents on the chest, allowing for fine-tuned temperature control. The multistage zipper system offers various configurations to adjust the bag's temperature without direct exposure to cold air.

Plus, the Blanket Fold draft collar optimizes sleep temperature by blocking cold air when tucked in and releasing excess heat when pushed out. The Riff is made with water-resistant, RDS-certified down and 100% recyclable materials.

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Looking for maximum comfort and lightweight packability across the seasons? Look no further than the Parsec 20 °F/-6 °C Ultralight Sleeping Bag, weighing just 1 lb. 12 oz. This bag excels in wet weather with its 800-fill Nikwax Hydrophobic Down, absorbing 90% less water and drying three times faster than untreated down.

The Parsec's SynergyLink™ Connectors provide a secure connection to your sleeping pad, preventing shifting and ensuring optimal thermal efficiency. Heat-mapped zoned insulation allocates warmth where it's needed most, while features like the Toe-asis™ Foot Warmer pocket and heat-trapping draft collars enhance comfort.

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When comfort is paramount, the Spark 30 °F/-1 °C Ultralight Sleeping Bag by Sea to Summit has got you covered. Crafted with premium 850+ fill power goose down, and treated with Ultra Dry Down, the Spark ensures exceptional insulation even in damp conditions.

With its lightweight, mummy fit design, RDS-certified down insulation, and thoughtful features, the Spark is an excellent option for adventurers seeking warmth, compactness, and comfort. Did we mention it clocks in at just over 1lb?

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The Phantom 30 °F/-1 °C Ultralight Sleeping Bag by Mountain Hardwear is your ultimate alpine companion, whether you're tackling high-alpine traverses, backcountry hut trips, or multi-week backpacking adventures.

Crafted with the same 100% recycled shell as the renowned Ghost Whisperer series, this bag combines exceptional performance with environmental responsibility. Packed with RDS-certified 800-fill down insulation, it offers an unparalleled warmth-to-weight ratio to keep you cozy in any environment. Weighs just 1 lb. 6 oz.

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More options from the Phantom line

Comparison and Evaluation Criteria

Each of our top picks offers unique features tailored to different preferences and needs. Let’s see how they stack up.

  • Performance

All five perform well across various weather conditions, with features like water-resistant shells, hydrophobic down insulation, and temperature ratings suitable for three-season or alpine use. The Hyperion, Riff, Parsec, Spark, and Phantom sleeping bags excel in providing warmth, comfort, and protection against moisture.

  • Comfort and Fit

The Hyperion offers a comfort fit with its longer zipper and ergonomic shape, while the Riff and Parsec provide extra room at the elbows and knees for side sleepers. The Spark and Phantom feature mummy fit designs for maximum thermal efficiency and snugness, ensuring a cozy night’s sleep even in cold or windy conditions.

  • Longevity and Durability

The Hyperion, Riff, Parsec, Spark, and Phantom all use high-quality fabrics, water-resistant treatments, and responsible down insulation to enhance durability and longevity. Whichever you choose, don’t forget to wash your sleeping bag at the end of every camping season to maximize longevity.

  • Sustainability

Sustainability is a key focus across the product lineup, with features like recycled materials, responsible down certification, and eco-friendly treatments. The Parsec, Spark, and Phantom boast recycled shells and RDS-certified down insulation, while the Riff incorporates GRS-certified recycled nylon and the Hyperion offers RDS-certification.


Choosing the right ultralight sleeping bag is essential for a comfortable and memorable outdoor adventure. By understanding key factors such as weight-to-warmth ratio, insulation type, shell material, and packability, you can make an informed decision that best suits your needs.

Our top picks for 2024 provide excellent options to keep you warm and well-rested without adding unnecessary ounces. But, if weight isn’t an issue, check out our other favourite sleeping bags.