Updated on January 13, 2024

When you’re out in the backcountry, there’s nothing better than wrapping up in one of the best synthetic sleeping bags money can buy after a long day of trekking in the mountains. Oftentimes, sleeping under the stars in a nice, warm bag is what hikers look forward to most.

A synthetic sleeping bag is a reliable and eco-friendly choice for your nights spent outside. Synthetic bags mean that they are stuffed with material that wasn’t derived from animals, and oftentimes the fabric these bags are shelled with is eco-friendly, too.

There are some benefits to synthetic sleeping bags like a hood, dual zipper systems, and loft (think cushiness, like a big, fluffy blanket!). But what factors are most important to you?

That’s up to you to figure out, but The Adventure Junkies broke down the ten best synthetic sleeping bags to help you start your search. Whether you’re looking for something lightweight or something that will keep you warm in temperatures down to 0 degrees F, we’ve got what you’re looking for here.

For a complete analysis of all backpacking sleeping bags, check out the buyer’s guide Best Backpacking Sleeping Bags.


Quick Answer - The Best Synthetic Sleeping Bags

  1. Nemo Forte 35
  2. Marmot Trestles 0
  3. Therm-a-Rest Space Cowboy 45
  4. Marmot Nanowave 45
  5. REI Co-op Trailbreak 20
  6. The North Face Cat’s Meow 22
  7. The North Face One Bag
  8. Exped MegaSleep 25
  9. Big Agnes Lost Dog 15
  10. Sea to Summit Trailhead ThII 30


Comparison Table - Best Synthetic Sleeping Bag

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NameTemp RatingWeightShapePriceRatingReview
Nemo Forte 3540 F2.1 lbsSemi-rectangular$1604.7Read Review
Marmot Trestles 015 F4.6 lbsMummy$1994.6Read Review
Therm-a-Rest Space Cowboy 4552 F1.2 lbsMummy$1404.6Read Review
Marmot Nanowave 4556 F1.8 lbsMummy$794.2Read Review
REI Co-op Trailbreak 2029 F3.4 lbsMummy$1094.4Read Review
The North Face Cat’s Meow 2231 F2.2 lbsMummy$1694.5Read Review
The North Face One Bag29 F3.7 lbsSemi-Rectangular$2904.4Read Review
Exped MegaSleep 2525 F2.3 lbsRectangular$1504.0Read Review
Big Agnes Lost Dog 1515 F3.1 lbsSemi-rectangular$2004.6Read Review
Sea to Summit Trailhead ThII 3040 F2.3 lbsSemi-rectangular$1494.1Read Review
NameTemp RatingWeightShapePriceRatingReview

Temp ratings refer to the EN or ISO Comfort rating.

Weight and price are shown for the regular size.

Want to learn more about a technical term? Check out our Features Explained section below.

Need buying advice? Take a look at these Things to Consider.

Reviews - The Best Synthetic Backpacking Sleeping Bag

Nemo Forte 35

View Women's Version
  • Insulation: Synthetic
  • Weight: 2.1 lbs
  • Shape: Semi-rectangular
  • Temp Rating: 40 F
  • 80% postconsumer recycled content.
  • Unique Spoon™ shaped bags offer more room at the elbows and knees, allowing side sleepers to shift positions comfortably throughout the night.
  • Waterproof/breathable foot-box withstands tent condensation, keeping feet warm and dry.
Nemo Forte 35 Summer Sleeping Bag

The Nemo Forte 35 is an affordable synthetic sleeping bag that has plenty of room for those who love to sprawl out. This bag is a great option for mild weather adventures where you don’t have to travel too far to get to your campsite. 

What we love the most about this bag is its spacious dimensions. If you’ve ever felt trapped in a narrow mummy bag, you’ll love the Forte’s hourglass shape that is wider at the shoulders and feet and slightly tapered at the hips. This design is perfect for side sleepers or people who tend to move around a lot at night. We also loved what NEMO calls thermo gills, they are zips that let the insulation spread apart which is great for warm summer nights.

The biggest drawback of this bag is its weight and pack size. At 2lbs 2 oz, it’s not the best choice for long distance backpacking but is manageable for overnight trips. The Forte uses Primaloft synthetic insulation which has its pros and cons. It doesn’t pack down as small as down but it is far more affordable.

If you love the idea of this bag but wish it had down insulation, check out the Nemo Disco line

This sleeping bag also comes in a 20 degree version.

The Nemo Forte also comes in a women’s specific version in both 20 degree and 35 degree versions.  

Marmot Trestles 0

  • Insulation: Synthetic
  • Weight: 4.6 lbs
  • Shape: Mummy
  • Temp Rating: 15 F
  • Shell: Polyester
  • Stuff Sack Size: 9.5 x 21 Inches
  • Zipper Location: Left
  • Fitted Hood Provides Warmth
  • External Stash Pocket Stores Your Valuables
  • Zipper Guard Prevents Bag From Snagging While Zipping And Unzipping
  • Vaulted Footbox Provides Warmth

The Marmot Trestles 0 sleeping bag is a great option for someone looking for a bag that will keep them warm in frigid temperatures, but doesn’t want to break the bank to invest in an expensive cold weather bag.

This bag is rated to keep you warm in temperatures down to 0°F, so it’s a great bag to take with you to the Cascades in Washington or the Sierra Nevadas in California. The bag itself will keep you toasty and cozy and the hood of the bag will provide extra heat for you.

This bag is made with quality material, including a zipper guard to make sure it won’t snag on your bag when you’re zipping it up. A 3D foodbox at the bottom provides warmth, and will also keep you comfortable by providing enough space at your feet so you won’t feel like you’re sardined into a bag.

This bag is a bit heavy, with the regular size weighing in at about 4 ½ lbs, but it sells at a killer price point. It can be hard to find a reliable backpacking sleeping bag for under $150 and, which is why this is a great option for hikers on a budget.

Therm-a-Rest Space Cowboy 45

  • Insulation: Down
  • Weight: 1.2 lbs
  • Shape: Mummy
  • Temp Rating: 52 F
  • Snag Free Zipper
  • Highly Compressible
  • Cinchable Hood For Increased Warmth

The Therm-a-Rest Space Cowboy 45 is one of the very few sleeping bags with water-resistant synthetic filling. This allows it to increase insulation – even when wet –  while decreasing weight. However, it is designed for summer camping, as it withstands only 45°F. The bag features ThermaCapture zoned insulation that is strategically placed to catch your body’s own rising heat. You can also cinch the hood down around your head for a snuggly, draft-free rest.

To increase versatility, this sleeping bag has loops that you can use to layer more quilts and blankets on it, making it useful in colder conditions. The zipper is snag-free to ensure its durability and ease of use. The Cowboy 45 weighs 1.5 lbs. – average for ultralight sleeping bags – but it can be compressed down to 2 liters of volume, saving lots of valuable space in your backpack.

Marmot Nanowave 45

  • Insulation: Synthetic
  • Weight: 1.8 lbs
  • Shape: Mummy
  • Temp Rating: 56 F
  • Draft tube keeps cold air from seeping through zipper
  • Zipper wraps around foot box
  • Synthetic insulation traps warmth even when wet
Marmot Nanowave Summer Sleeping Bag

The Marmot Nanowave 45 is an affordable summer sleeping bag that won’t take up too much room in your backpack. Not only is it cheap, it’s also practical and functional.

In awarding it the winner of the best under $100 category, we realize it’s not quite fair because most other bags on this list have a temperature rating down to around 20 degrees. However, if you’re on a super tight budget and plan to camp from mid-spring to mid-fall, the Nanowave 45 is hard to beat.

Which leads us to the biggest downside of this bag, it is only good in mild weather. But, not everyone needs or wants a super warm bag and if you combine the Nanowave with an extra warm sleeping pad and a thermal liner, you might be able to extend the temperature range of this bag down a few degrees, making it much more versatile. If you’re looking for a warmer budget backpacking sleeping bag, check out the REI Trailbreak 20.

The Marmot Nanowave is also available in a 55-degree and 35-degree version.

REI Co-op Trailbreak 20

View Women's Version
  • Fill Weight: N/A
  • Insulation: Synthetic
  • Weight: 3.4 lbs
  • Shape: Mummy
  • Volume: 12.0 L
  • Temp Rating: 29 F
  • Fill Power: Polyester
  • Water-resistant synthetic fill
  • 3-panel hood
  • Stuff sack included
REI Trailbreak 20 Backpacking Sleeping Bag

The REI Co-op Trailbreak 20 is a budget minded synthetic sleeping bag that was designed for people who are just starting out backpacking. 

Just because this bag is a steal doesn’t doesn’t mean that it is cheap. While the Trailbreak 20 is nowhere near as light, comfortable or packable as the bags at the top of our list, we have to give it credit for being an exceptional value. Its size and weight is manageable for short backpacking trips.

The cash savings do come with some drawbacks.The lining fabric is a bit rough making it much less comfortable than the silky fabric found on many other bags. Also, it doesn’t have a neck baffle, so some heat does escape through the top of the bag. One last nitpick, the Trailbreak doesn’t come with a compression sack, so you’ll need to calculate that into your decision. If you’re on a tight budget and just can’t spring for a better sleeping bag right now, this is a good option to get you out on the trail fast.

Looking for a summer sleeping bag? The REI Trailbreak is also available in a 30-degree version.

The REI Trailbreak comes in a women’s specific which is available as a 20-degree or 30-degree bag

The North Face Cat’s Meow 22

  • Weight: 2.2 lbs
  • Shape: Mummy
  • Temp Rating: 31 F
  • Shell: Ripstop Nylon
  • Stuff Sack Size: 9 x 16 Inches
  • Zipper Location: Left
  • Fitted Hood Provides Warmth
  • No-Draft Collar Prevents Heat Loss
  • Vaulted Footbox Provides Warmth
The North Face Cat's Meow 22

The North Face Cat’s Meow is a great option for someone who tends to venture into the outdoors in the spring/summer seasons.

The shell of this bag is made with ripstop nylon, which is a tougher fabric than polyester or just plain nylon, and will ensure your bag won’t shed on you in rocky terrain when you might be camping under the stars instead of inside your tent. 

A fitted hood will provide warmth and can serve as extra cushioning for your head when you lay it down to sleep. There is also a draft collar that will provide extra heat and will prevent heat loss throughout the night.

This bag isn’t going to be the warmest option featured by The Adventure Junkies, so if you know you sleep cold, or you like to hike in the fall/winter season and are looking for a bag to keep you warm at high alpine levels, this may not be the bag for you.

The North Face One Bag

  • Insulation: Down / Synthetic
  • Weight: 3.7 lbs
  • Shape: Semi-Rectangular
  • Temp Rating: 29 F
  • Shell: Nylon
  • Stuff Sack Size: N/A
  • Zipper Location: Left
  • Three Bags In One Means You’ll Always Be Prepared, No Matter The Weather
  • Non-snag Zippers Make It Easy To Transition Between Configurations
  • Bottom Layer Rolls Up Into A Pillow If You Don’t Need The Added Warmth

A great bag for any season, The North Face One Bag Sleeping Bag will keep you warm in just about any temperature you can imagine sleeping in down to 5° F. Although there is technically a down layer included in this 3-in-1 bag, we still think the synthetic outer layer makes this one of the best synthetic bag choices on the market today. 

This bag has easy-to-use zippers, so configuring the bags just the way you want them will be a breeze. For mild summer nights, you can opt to use only the super lightweight 40° F outer layer on its own. If there’s a chill in the air, you can pair the blue outer layer with the removable yellow mid-layer and stay warm down to 20°F. And if you’re an extreme camper who loves sleeping outside during the wintertime, then use all three bags for warmth in temperatures down to 5°F!

This is certainly the most versatile bag on the list and it’s very popular among both car campers and backpackers because it just about meets all your wilderness sleeping needs!

Exped MegaSleep 25

  • Insulation: Synthetic
  • Weight: 2.3 lbs
  • Shape: Rectangular
  • Temp Rating: 25 F
  • Shell: Ripstop Nylon
  • Stuff Sack Size: 22 x 12 Inches
  • Zipper Location: Left/Right
  • Zippers On Both Sides Of Bag Makes It Easy To Get In And Out And Control Temperature
  • Draft Tube Along Zipper Prevents Heat Loss
  • Quick-Drying Insulation Means You Won’t Need To Worry If This Bag Gets Wet

The Exped MegaSleep 25 Sleeping Bag is a versatile option for anyone who likes to camp or backpack.

Weighing in at about 2 ½ pounds, this bag isn’t too heavy for a pack, and won’t take up too much space either. The bag has zippers down both sides, so you can get in and out of it easily, and adjust the temperature easily according to your preference. 

This bag is a rectangle shape, so you will have plenty of room to spread out, no matter what your favorite sleeping position is. There is a draft tube along both zippers in this bag that will help prevent heat loss and keep you cocooned into your bag at night. 

Tested to keep you warm down to 25° F, this bag is a great option for spring, summer, or fall camping or backpacking.

Big Agnes Lost Dog 15

  • Insulation: Synthetic
  • Weight: 3.1 lbs
  • Shape: Semi-rectangular
  • Temp Rating: 15 F
  • Spacious Footbox
  • Includes Mesh And Nylon Storage Sack
  • Two Way Zipper
  • Can Be Attached To Another Right-Zip Sleeping Bag

The Big Agnes Lost Dog is a cold-oriented sleeping bag that withstands temperatures up to 15°F. It uses FireLine ECO synthetic insulation made from recycled polyester, and the innovative design includes several features for comfort. It has a Free Range hood that allows you to lift your head while keeping a snug fit around your face. The Free Range foot box is similar, giving you some wiggle room. An additional no-draft collar will keep the cold wind out. 

For convenience, a Flex Pad Sleeve can stretch over an insulated sleeping pad for extra warmth. The bag also has a 2-way anti-snag zipper and can be joined with another right-zip sleeping bag. If that doesn’t sound comfy enough, the Lost Dog offers a Pillow Barn feature that makes sure your pillow stays put all night. Although it is on the pricier end of affordable, the extra features make it worth it.

Sea to Summit Trailhead ThII 30

  • Insulation: Synthetic
  • Weight: 2.3 lbs
  • Shape: Semi-rectangular
  • Temp Rating: 40 F
  • Extra Spacious
  • Second Zipper In Footbox
  • Full Length Zipper To Convert Sleeping Bag Into A Quilt

The Sea to Summit Trailhead ThII 30 is another synthetic sleeping bag that retains its insulation abilities even when wet. It uses a unique WaveLoft technique that tangles filling fibers for maximum heat retention up to 30°F. This bag has a tapered rectangular shape, providing you with comfort and room to move. An oversized anti-snag zipper draft tube will guard your whole body against cold chills when you snuggle down in this bag. 

An important characteristic of the THII 30 is its versatility. Its full-length zipper lets you turn this sleeping bag into a quilt. Furthermore, there is a second zipper in the foot box, allowing ventilation for your feet and broad temperature adjustability. Plus, to prevent your frustration, the bag’s lining fabric is directly attached to the shell fabric, which prevents zipper tangles.  This sleeping bag is excellent for backpacking since it weighs about 2.5 lbs – not much more than most ultralight sleeping bags!





One of the best things about buying a synthetic sleeping bag is that it won’t break the bank the way a down sleeping bag would. You can find a reliable synthetic sleeping bag at a very reasonable price for $100 or less.

Sleeping bags that are a higher cost than this probably have more features than others. For example, they might have a double size zipper, ventilation options, or a hood. Define what features are most important to you and think about how much you can afford to invest in your sleep system, and go from there.



The synthetic sleeping bags that will keep you warm in colder temperatures are usually going to weigh more than those that aren’t. But if you’re going to be trekking in alpine heights, or you’re into mountaineering, getting a bag with a proper temperature rating could mean the difference between life and hypothermia.

The temperature rating is arguably the most important thing to consider when buying a sleeping bag. Know where you’re planning to camp and figure out what the temperature there will be like, and take into consideration that the higher the elevation, the lower the temperature. Then choose a bag that is rated to keep you warm in temperatures at least 10° F below the coldest temperature you’re expecting to sleep in.

Check out this article from REI for more info about how to pick a sleeping bag temperature.



One of the drawbacks to a synthetic sleeping bag is that they tend to be fairly heavy. They are heavier than down sleeping bags, but much more affordable, and you can still find a middle ground between weight, warmth, and cost.

Knowing the weight of the other items in your pack will help you decide how heavy of a bag you can buy. Determine your base weight. This is the weight of everything in your pack minus food and water. Then, add everything up minus your sleeping bag. This should give you a target of what to look for.

A sleeping bag is one of the most important items you can put in your pack, so make sure to give it a decent allotment in the weight game.



Ripstop nylon is the strongest of shell fabric featured in this article. This material is tough and durable and will last you for ages.

Nylon is also a great option, as it’s a durable lightweight fabric. Polyester is the third shell fabric featured in this article, and it’s still a durable option, but a little bit heavier than nylon.

All in all, don’t get too caught up about the shell fabric of your sleeping bag unless you’re going to be hiking in really rugged terrain or tend to camp under the stars where your bag could suffer from shredding on rocks or branches.



Most sleeping bags are tailored to fit a 6 foot hiker or smaller. If you like your bag to be a bit roomier, then a long size would be a better option for you.

If you’re shorter than 5 foot, it might be a good idea to get a short bag – save yourself weight and space in your pack!

Rectangular shaped bags will offer more room for moving around while you’re sleeping, so if you know you’re an active sleeper, you should consider a rectangular or semi-rectangular shaped bag. Mummy bags are going to be more lightweight, but are more restrictive for sleeping options.





The mummy style is one of the most popular designs for backpacking sleeping bags. This design follows the shape of your body. The bag is wider around your shoulders and head, and slimmer towards your legs and feet.

The mummy style is most comfortable for hikers who sleep on either their backs or their stomachs. They are also the warmest option available in terms of sleeping bag shape.


Fitted hood

A fitted hood is a huge plus for a synthetic sleeping bag. It will give your head some loft and warmth and can help serve as a pillow bank. I mean, who doesn’t want a warm fluffy hood covering their head while they sleep?

Some of the hoods on the synthetic bags featured in this article have a drawstring cord. With them, you can tighten the hood to your preference of fit.


External stash pocket

An external stash pocket on a synthetic sleeping bag is a pocket on the exterior of the bag for added gear storage.


Vaulted footbox

A vaulted footbox is a part of the bag that encapsulates your feet. It provides loft underneath them to keep them warm. It also helps blood flow evenly while you’re sleeping. After a long day of trekking in the mountains, you don’t want to have to worry about the comfortability of your feet. A vaulted footbox is a sure thing for comfort.


No draft collar

A no draft collar in a synthetic sleeping bag is an extra layer of material that’s been added around the neck portion of the bag to prevent heat from escaping and to not let cold air in.


Semi rectangular

The semi-rectangular shape of a synthetic sleeping bag is a mix between a rectangular shape and a mummy bag. It offers a little more room for those who are active sleepers without taking up too much space in your pack.


Liner loops

Liner loops are featured in a couple of the synthetic sleeping bags in this article. These are internal loops inside the sleeping bag that you can tie your sleeping bag liner to to prevent it from falling down while you’re sleeping.

If you’re an active sleeper and you find your sleeping bag liner often at the bottom of your bag when you wake up, these would be a huge plus. If you don’t sleep with a liner, they could be unnecessary.

Check out this article for more info about the benefits of sleeping bag liners.


Sleeping pad sleeve

A sleeping pad sleeve is an extra layer of material that’s attached to the bottom of a synthetic sleeping bag that can hold your sleeping pad. This assures that your sleeping pad won’t move about while you’re sleeping, and will prevent you from rolling off.