When it comes to backpacking, every ounce of weight counts. Ultralight backpacking is all about shedding unnecessary weight from your gear to maximize your speed, agility, and endurance on the trail. One of the most critical things to dial in for any backpacker is their sleep system, which includes a sleeping pad and a sleeping bag. Unfortunately, many sleeping bags can be heavy and bulky to toss in a backpacking backpack, where space is pretty limited, which can be tiring to carry on long treks.

That's where ultralight sleeping bags come in, providing a lightweight and compact solution that won't weigh you down on the trail. In this guide, we'll explore the world of ultralight sleeping bags, examining the key features to consider when choosing one and providing recommendations for some of the best options on the market.

Who Needs an Ultralight Sleeping Bag?

If you’re wondering if an ultralight sleeping bag is the right option for you, here are a few of the main people who would benefit from having an ultralight bag!

1. Ultralight backpackers: People who are dedicated to reducing the weight of their gear as much as possible and willing to make sacrifices in comfort to do so. Ultralight backpackers often aim to cover long distances quickly, and an ultralight sleeping bag is a crucial part of their kit.
2. Thru-hikers: People who undertake long-distance hikes, such as the Appalachian Trail or Pacific Crest Trail, where every ounce of weight counts. An ultralight sleeping bag can help them move more quickly and efficiently on the trail.
3. Minimalist travelers: People who prefer to travel light and don't want to be weighed down by bulky gear. An ultralight sleeping bag is an essential item for those who want to travel with just a backpack and minimal belongings.
4. Adventure travelers: People who like to explore remote areas and want to be able to carry everything they need on their backs. An ultralight sleeping bag is a valuable piece of gear for those who want to enjoy a comfortable night's sleep in the great outdoors without carrying unnecessary weight.

Key Factors to Consider When Choosing an Ultralight Sleeping Bag

Temperature Rating

Ultralight sleeping bags are available in a range of temperature ratings, from summer bags rated for warmer temperatures to four-season bags rated for below-freezing conditions. A sleeping bag's temperature rating is determined by the lowest temperature at which a person can comfortably sleep inside the bag, based on the bag's insulation and design. So choose a sleeping bag with a temperature rating appropriate for the climate and conditions you'll be camping in.

Here are the most common temperature rating ranges for sleeping bags:

• Summer bags: Rated for temperatures above 35°F (2°C)
• Three-season bags: Rated for temperatures between 20°F (-7°C) and 35°F (2°C)
• Winter bags: Rated for temperatures below 20°F (-7°C)

It's important to note that temperature ratings are not standardized across all manufacturers, so a 20°F sleeping bag from one brand may not provide the same level of warmth as a 20°F sleeping bag from another brand. In addition, factors such as the quality and type of insulation, the shape of the bag, and the design of the hood and draft collar can all affect the warmth of a particular bag.

Insulation Type

The two main types of insulation used in ultralight sleeping bags are down and synthetic. Down is lighter and more compressible but can lose its insulating properties when wet. Usually made of polyester, synthetic insulation is heavier and less compressible, but it retains warmth even when wet. Some down bags have a water-resistant or water-repellent down, such as DownTek, which has the lightweight/compressible features of classic down, but still retains some heat and insulation capabilities when wet.

Fill Power

If you choose a down sleeping bag, look for one with a high fill power. Fill power or fill weight refers to the loft or fluffiness of the down, and higher fill power means more warmth with less weight.

Weight and Packed Size

An ultralight sleeping bag's weight and packed size are important factors to consider, as they will affect how easy it is to carry on a backpacking trip. Therefore, look for a lightweight sleeping bag that packs down small.

Ultralight Sleeping Bag Features

Some ultralight sleeping bags come with additional features. Here are some of the most common features you’ll see on an ultralight sleeping bag:

1. Shape: Sleeping bags come in different shapes, including rectangular, mummy, and semi-rectangular. Mummy bags are more thermally efficient and lightweight, while rectangular bags offer more room for movement and are more comfortable.
2. Hood: A hood is a part of the sleeping bag that covers your head and provides additional insulation. It is especially important for cold weather conditions. Some hoods have an elastic draw cord around the outside, allowing for a closer fit to keep cold air out.
3. Zipper: The zipper allows you to open and close the sleeping bag. Some bags have a full-length zipper, which allows for easy ventilation, while some have a shorter zipper which can help retain heat.
4. Draft collar: A draft collar is a tube of insulation that sits around the neck and prevents heat loss through the neck opening of the sleeping bag.
5. Draft tube: A draft tube is a layer of insulation that sits behind the zipper and prevents cold air from seeping in.
6. Footbox: The footbox is a part of the sleeping bag that is designed to fit around your feet and provide additional insulation.
7. Stuff sack: A stuff sack is a bag that allows you to compress the sleeping bag for easier transport and storage. It can also protect the sleeping bag from moisture and dirt. Most sleeping bags come with a stuff sack.

Now that you understand some of the key features and differences in ultralight sleeping bags, let’s get into the list of the most recommended ones!

The 8 Best Ultralight Sleeping Bags

1. Western Mountaineering UltraLite

The Western Mountaineering UltraLite is one of the most popular and best ultralight sleeping bags on the market. It’s filled with high-quality 850+ fill power goose down and lightweight and durable nylon face fabric. Its efficient design helps minimize weight and bulk while providing one of the best warmth-to-weight ratios out of any ultralight sleeping bag. Western Mountaineering is a high-end brand with a higher price tag than most brands, but its quality makes it worth the money!

• Weight: 1lb 13oz
• Length: 6’0”
• Temperature rating: 20°F/-6°C

2. Therm-a-Rest Hyperion

The Therm-a-Rest Hyperion is an ultralight mummy bag and weighs just 1lb 5oz, making it one of the lightest bags available. In addition, it features high-quality 900-fill-power Nikwax hydrophobic down insulation and a breathable shell fabric to keep you warm and dry. It also has a comfort footbox, draft collar, and unique SynergyLink Connectors, allowing you to attach it to your sleeping pad for added comfort.

• Weight: 1lb 5oz
• Length: 6’0”
• Temperature rating: 20°F/-6°C

3. Big Agnes Mystic Ultralight 15° Sleeping Bag

This sleeping bag is designed for those who want to minimize weight without sacrificing warmth and comfort. It features an 850-fill DownTek water-repellent down insulation and a unique baffle construction that eliminates cold spots. The bag also includes a minimalist hood, a draft tube to keep cold air out, and a built-in pillow pocket and hood for added comfort.

• Weight: 1lb 13oz
• Length: 6’5”
• Temperature rating: 15°F/-9°C

4. Big Agnes Lost Ranger Ultralight 3N1 15

The Big Agnes Lost Ranger Ultralight 3N1 15 sleeping bag is a versatile option for campers who tend to get outside in a variety of temperatures. It features 650-fill DownTek water-repellent down insulation and a lightweight ripstop nylon shell. What makes this bag unique is its 3-in-1 design that allows you to use the entire sleeping bag for colder temperatures or remove the outer layer or inner quilt for warmer conditions. In addition, the integrated sleeve fits a 20-inch sleeping pad and prevents you from rolling off during the night.

• Weight: 2lbs 6oz
• Length: 6’5”
• Temperature rating: 15°F/-9°C

5. Exped Ultralite 3C/37F Sleeping Bag

The Exped Ultralite 3C/37F Sleeping Bag is a lightweight and packable option for camping in warmer temperatures. It features 800-fill-power RDS (Responsible Down Standard) certified goose-down insulation and a lightweight ripstop nylon shell. This is a great option for broader campers who have had a hard time finding a bag that doesn’t feel constricting on the shoulders and hips, as its roomy cut provides ample space for movement. The included stuff sack doubles as a pillow for added convenience.

• Weight: 1lb 7oz
• Length: 6’0”
• Temperature rating: 37°F/3°C

6. Feathered Friends Flicker 20 UL

The Flicker 20 UL sleeping bag is another very versatile option for backpackers. It features 950-fill-power goose-down insulation and a lightweight Pertex Quantum shell. Similar to the Big Agnes Lost Ranger, though slightly different, this bag has a very versatile design that allows it to be used as a quilt, a fully enclosed sleeping bag, or a hoodless sleeping bag. The included draft collar and zipper draft tube keep you warm in colder temperatures, while the ability to unzip and use it as a quilt or blanket provides ventilation in warmer conditions.

• Weight: 1lb 8oz
• Length: 6’0”
• Temperature rating: 20°F/-6°C

7. Big Agnes Torchlight UL 20

Another good option for broader campers is the Big Agnes Torchlight UL 20. It features an expandable design to provide extra space, up to 10 inches, when needed. In addition, it features 850-fill DownTek water-repellent down insulation and a lightweight ripstop nylon shell. The integrated sleeve fits a 20-inch sleeping pad.

• Weight: 2lbs 1oz
• Length: 6’0”
• Temperature rating: 20°F/-6°C

8. Marmot Hydrogen

The Marmot Hydrogen is an ultralight sleeping bag with 800-fill power goose down. Its design includes a full-length zipper for easy entry and exit, a draft collar, and a 3D hood (meant to be more precisely contoured to fit your head shape, to keep the cold air outside and the warm air inside).

• Weight: 1lb 10oz
• Length: 6’0”
• Temperature rating: 30°F/-1°C

Conclusion

As you can see, a wide range of options is available for ultralight sleeping bags! It can be overwhelming, but understanding the key features and materials can help you choose the right sleeping bag for your needs. If you still need help or have any other camping or hiking-related questions, reach out to a Camping and Hiking Expert here on Curated, and we would be happy to answer all of your questions!