Which mummy sleeping bag is best?

A mummy sleeping bag includes an insulated hood that cinches around the face. The form-fitting bag hugs the body, trapping warm air to ensure you get the best possible night’s sleep while on the trail. The best models use the latest filler technologies to keep the bag as light and compact as possible when packed down. This makes mummy sleeping bags ideal for trekking, biking, climbing and any other active pursuit that requires you to carry your equipment. If you are looking for a good-value down bag for all seasons, consider the excellent Marmot Ironwood model.

What to know before you buy a mummy sleeping bag

Different fill types

The best mummy sleeping bags are filled with either duck or goose down, which is the soft plumage that lies beneath the feathers. Duck down is less expensive, as it is not as fine as goose down, which is lighter, more compact and has slightly better insulating properties. Check a mummy sleeping bag’s fill power rating to see how many cubic inches of down it has per ounce. The higher the fill power, the warmer the bag. Synthetic polyester fibers are used in cheaper models as an alternative to down sleeping bags. This does have its benefits as it is quick-drying, very lightweight and easy to clean.

Shell construction

Sleeping bag outer shells are usually made from tough ripstop polyester, which is breathable, light and durable. Sometimes this is impregnated with a hydrophobic chemical to repel water, which can be essential in extreme weather conditions. The shell is usually stitched through to the lining to maintain the positional integrity of the filler. This is especially effective in down-filled bags, as it keeps it in place. Often stitched boxes, known as baffles, are created to further prevent cold spots. 

Sleeping bag rating

Sleeping bags often carry a survival rating and a comfort rating in degrees Celsius, Fahrenheit or both. The former suggests the temperature at which a user can expect to survive in the sleeping bag, while the latter refers to the temperature at which a person can expect to get a pleasant night’s sleep, without being too cold. You’ll often see seasonal ratings as well, rated from one to five. While these don’t refer to seasons by name, a one-season bag is effective during summer months and a four-season bag will carry you through the year, with a five-season bag being ideal for extreme conditions.  

What to look for in a quality mummy sleeping bag


The weight of your sleeping bag can be an important factor if you are using it for hiking, mountaineering, or other active pursuits. The weight of a sleeping bag is usually dictated by the type of filler it uses and the higher the down quality, the lighter the bag is. Therefore, most premium mummy sleeping bags use very high-quality goose down for the best possible weight-to-warmth ratio, while synthetic fillers, while very lightweight, require a compromise on warmth.

Additional features

A mummy sleeping bag might include a shoulder baffle with a drawstring to cinch the bag around the collar and lock in warm air below the neckline. A draft tube should run the length of the zipper to prevent cold air from entering. Many also have small zippered pockets on the inside which are handy for keeping essentials such as phones or medication close at hand. The best bags also have compression sacks with webbing straps on the outside to fully compress the bag during transit.

Packed size

The size of the bag when packed is important when engaged in active pursuits, but is also a consideration for anyone that has a limited luggage capacity. A sleeping bag’s packed size is usually measured by its volume in liters. There is great variance in sizes, depending on which type of filler is used, with some bags being as small as 5 liters in volume and others being as large as 13 liters when packed.

How much you can expect to spend on a mummy sleeping bag

A basic mummy sleeping bag with synthetic filler costs $30-$50. Expect to pay $70-$150 for a high-quality synthetic-filled bag or a midrange duck-down sleeping bag. The best mummy sleeping bags with goose down cost upward of $200.

Mummy sleeping bag FAQ

Which is better – synthetic or down filler?

A. Both options have their benefits, with down filler being warmer and lighter and synthetic filler being cheaper and quick-drying. If you are buying on a budget, you must reach a compromise between size, weight and warmth, but if money is no option, choose a down-filled mummy sleeping bag.

How do you care for my mummy sleeping bag?

A. Sleeping bag manufacturers usually recommend hand-washing or a machine wash on a delicate cycle. Dry-cleaning should be avoided, as the chemicals can damage delicate filler. Tumble drying on low heat is very effective as it fluffs the down nicely, improving its insulating properties.

What’s the best mummy sleeping bag to buy?

Top mummy sleeping bag

Marmot Ironwood

Marmot Ironwood

What you need to know: This ultralight down mummy sleeping bag has water-resistant properties, making it well-suited for use in extreme conditions on the trail.

What you’ll love: The Ironwood has 650-fill power down, giving a comfort rating of 20 degrees, and has plenty of legroom and an anatomically-optimized footbox for extra comfort. It has a snag-free draft tube to prevent its YKK zippers from sticking and an internal stash pocket to keep your essentials close.

What you should consider: Its polyester stuff sack has no additional compression straps; however, it does include a mesh bag for storage.

Where to buy: Sold by Amazon

Top mummy sleeping bag for the money

Teton Sports TrailHead

Teton Sports TrailHead

What you need to know: The affordable Trailhead has all the essential features and is ideal for casual use during warmer months of the year.

What you’ll love: The brightly-colored ripstop nylon shell is durable and includes a drawstring at the hood. On the inside, the bag is backed by a soft and breathable lining with draft tubes along the zippers to help contain the warmth. 

What you should consider: This model has a synthetic filler that does not perform as well as down in colder conditions.

Where to buy: Sold by Amazon

Worth checking out

Kelty Cosmic Ultralight

Kelty Cosmic Ultralight

What you need to know: This professional-quality option has 600-fill drawdown filler, which has an excellent weight-to-warmth ratio and is easy to compress, making it ideal for active pursuits.

What you’ll love: Each piece of down in this mummy sleeping bag has hydrophobic treatment, which means it dries quicker and repels water, rather than absorbs it. Its excellent thermal properties are enhanced by two-way locking zippers and a highly-insulated hood.

What you should consider: It may run a little tight across the chest if used by larger people.

Where to buy: Sold by Amazon


Sign up here to receive the BestReviews weekly newsletter for useful advice on new products and noteworthy deals.

Luke Mitchell writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

Copyright 2021 BestReviews, a Nexstar company. All rights reserved.