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
- Nemo Forte 35
- Marmot Trestles 0
- Therm-a-Rest Space Cowboy 45
- Marmot Nanowave 45
- REI Co-op Trailbreak 20
Comparison Table - Best Synthetic Sleeping Bag
For the best experience turn your device horizontally| Name | Temp Rating | Weight | Shape | Price | Rating | Review |
|---|---|---|---|---|---|---|
| Nemo Forte 35 | 40 F | 2.1 lbs | Semi-rectangular | $160 | 4.7 | Read Review |
| Marmot Trestles 0 | 15 F | 4.6 lbs | Mummy | $147 | 4.6 | Read Review |
| Therm-a-Rest Space Cowboy 45 | 52 F | 1.2 lbs | Mummy | $140 | 4.5 | Read Review |
| Marmot Nanowave 45 | 56 F | 1.8 lbs | Mummy | $79 | 4.2 | Read Review |
| REI Co-op Trailbreak 20 | 29 F | 3.4 lbs | Mummy | $109 | 4.4 | Read Review |
| Name | Temp Rating | Weight | Shape | Price | Rating | Review |
Temp ratings refer to the EN or ISO Comfort rating.
Weight and price are shown for the regular size.
Reviews - The Best Synthetic Backpacking Sleeping Bag
Nemo Forte 35
Specs
- Insulation: Synthetic
- Weight: 2.1 lbs
- Shape: Semi-rectangular
- Temp Rating: 40 F
Features
- 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.
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
Specs
- Fill Weight: 41.2 oz
- Insulation: Synthetic
- Weight: 4.6 lbs
- Shape: Mummy
- Volume: 30.9 L
- Temp Rating: 15 F
- Fill Power: HL-ElixR
Features
- Low Weight And Small Packed Size
- Extra Warm
- Full Length Two-Way Zipper
BEST BUDGET WINTER SLEEPING BAG
The Marmot Trestles 0 is a real find for hikers wishing to explore cold environments. With a durable SpiraFil synthetic insulation, the sleeping bag will keep you warm at temperatures as low as 1.9°F. A 3D hood will provide warmth and comfort for your head; you can also cinch it tightly around your face during freezing nights. Another great feature of the Marmot Trestles is the foot box, which ensures extra comfort and warmth where it’s most needed.
The Trestles 0 has a full-length, two-way zipper built to prevent snagging. There is also a fold-down second zipper that provides fresh ventilation. In case you need anything during the night, there is an external stash pocket for your essentials. Additionally, the bag has two hang loops for storing or drying out the bag.
Therm-a-Rest Space Cowboy 45
Specs
- Fill Weight: 04.2 oz
- Insulation: Synthetic
- Weight: 1.2 lbs
- Shape: Mummy
- Volume: 02.0 L
- Temp Rating: 52 F
- Fill Power: Polyester
Features
- Water Resistant
- Highly Compressible
- Cinchable Hood And Snag Free Zipper
BEST LIGHTWEIGHT & BUDGET-FRIENDLY SLEEPING BAG
The Therm-A-Rest Space Cowboy 45 is an awesome ultralight mummy-shaped sleeping bag. Its compressed volume of 2 liters makes it highly packable and lightweight. Because this sleeping bag only withstands 45°F, it is better suited for warmer weather and summer camping. However, you can layer it with other quilts using blanket loops on the bag, expanding its versatility. Additional removable connectors even let you fasten a sleeping pad to the bag.
The Cowboy 45 uses water-resistant synthetic fill that retains its insulation abilities even when damp. It is strategically placed in certain areas to optimize warmth and weight. The ThermaCapture lining efficiently traps body heat. Additionally, a cinchable hood also guards against unwanted drafts. All these features make the Space Cowboy 45 a great companion for backcountry travels.
Marmot Nanowave 45
Specs
- Insulation: Synthetic
- Weight: 1.8 lbs
- Shape: Mummy
- Temp Rating: 56 F
Features
- Draft tube keeps cold air from seeping through zipper
- Zipper wraps around foot box
- Synthetic insulation traps warmth even when wet
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
Specs
- Fill Weight: N/A
- Insulation: Synthetic
- Weight: 3.4 lbs
- Shape: Mummy
- Volume: 12.0 L
- Temp Rating: 29 F
- Fill Power: Polyester
Features
- Water-resistant synthetic fill
- 3-panel hood
- Stuff sack included
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.
THINGS TO CONSIDER WHEN BUYING THE BEST SYNTHETIC SLEEPING BAGS
PRICE
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.
TEMPERATURE RATING
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.
WEIGHT
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.
SHELL FABRIC
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.
SIZE
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.
FEATURES EXPLAINED
Mummy
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.
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For more of our top hiking & backpacking gear recommendations, check out these popular buyer's guides:
Best Backpacking Sleeping Bags
Best Backpacking Sleeping Pads