Sleeping bags that feature full-length zippers and hoods that seal tightly against cold nights earn top marks from us, while quilts that can either be spread out as blankets or used partway as mummy bags also get our highest marks.

Many of the best lightweight bags offer excellent warmth-to-weight ratios, featuring premium down insulation and lightweight shell fabrics such as nylon. One notable bag, such as the NEMO Disco, features expandable foot gills.

Weight

Sleeping bags play an integral role in backpacking. From long distance journeys to trying to reduce the number of items in your pack, lightweight sleeping bags are an ideal choice.

Most bags on this list weigh under 2 lb, with several significantly lighter. If you’re searching for an ultralight sleeping bag that provides sufficient warmth for backpacking trips in freezing environments, this list could be your starting point.

Lightweight backpacking sleeping bags typically feature goose down insulation. The finest goose down has fluffy plumes that make it more space efficient than synthetic alternatives, and its fill power (listed in product descriptions) indicates its amount. A higher fill power, such as 800, will provide more warmth per ounce than lower ones (550 for instance), plus it compresses more compactly than some synthetic options.

Insulation

Sleeping bags that fall into this category typically reduce weight by combining high-quality insulation with reduced design and features, including down insulation with one of the best warmth-to-weight ratios available – such as Mountain Hardwear’s Phantom 0F which boasts nearly 2 pounds of 800-fill down insulation as well as a lofty draft collar and cinchable hood that protect against freezing environments and altitude-related chilliness.

Some bags can help save weight by tapering their shapes to accommodate more people in a smaller space and reduce fabric and insulation usage. When shopping, check for “compressed volume” specifications which indicate how much a bag packs down into its smallest size (and therefore has reduced weight and packed size).

Another useful spec is fill power, which measures how lofty or fluffy down clusters are. However, temperature ratings provide more reliable indicators of warmth – low fill power can still provide sufficient warmth for many backpackers.

Temperature Rating

Warmth-to-weight ratio in an ultralight sleeping bag varies significantly among manufacturers, though most manage to achieve weight savings through combination of high-grade insulation and reduced features and design. Most bags use either synthetic fill or down, with down typically providing superior warmth-to-weight ratio.

These lightweight sleeping bags feature shell fabrics made of ripstop nylon or polyester and most are coated with a water repellent finish to repel water, keeping you dry and warm inside your sleeping bag. There may also be waterproof varieties, while others allow moisture from your body to pass quickly through, keeping the insulation dry and warm.

Temperature rating is the key metric when choosing an ultralight sleeping bag, as this indicates how cold it will keep you comfortable while sleeping in it. All the bags in our review have comfort ratings of well below freezing for most conditions and some have even lower limits that will keep them comfortable even under more extreme circumstances.

Comfort

Lightweight bags may limit how warm they can be, but there are ways to increase warmth with minimal extra weight. Opting for higher-grade fill and semirectangular designs are two effective options that can increase warmth without significantly adding bulk.

Sleeping bags measure the warmth they provide using something called “fill power.” A lower number indicates less warmth for more weight while higher numbers indicate increased warmth at lower weight.

The best ultralight backpacking sleeping bags feature high-quality fabrics designed to be gentle on skin, ample room to move while sleeping and excellent warmth for their weight. In addition, these sleeping bags often include features designed to ensure optimal comfort such as baffles – sewn-in parts of the bag designed to prevent down displacement – designed to protect areas where movement occurs most frequently — such as the torso for side sleepers and feet for back sleepers – baffles are designed to prevent down from shifting as you move around inside them while straps provide secure connections between sleeping bags and pads or bag to pad connection options allowing maximum comfort during their adventures!