Ultralight sleeping bag test & comparison: the right outdoor sleeping bag will keep you nice and warm at night during your adventures in nature. How do you find the right sleeping bag for you and your needs?
Important characteristics for the purchase are: material, temperature range, pack size and weight. Of course, price also plays an important role. That’s why I’m introducing you to absolute all-rounders in this comparison, and together we’re also looking at exciting price tips! There’s a lot more to consider. What you should look for when choosing the right sleeping bag is clearly summarised in the advice section of this article. After reading you are an expert 😉
What is this about?
In the Outdoor Sleeping Bag Test you will find: 15 sleeping bags in a clear comparison. The sleeping bags are high quality, lightweight and weigh between 470 grams and 985 grams. This means they fit wonderfully in any backpack when hiking and any bikepacking bag when bikepacking. To make it easier for you, the comparison is divided into categories:
- Ultralight sleeping bags from 400 grams to 599 grams: The most versatile category in the Ultralight Sleeping Bag Test! These sleeping bags are true all-rounders and very versatile! The weight stays nice and light and the pack size is small. From early spring to late fall, sleeping bags in this category provide comfortable sleep. In combination with e.g. a down jacket and long merino wool underpants, comfortable sleeping up to about 0 degrees is possible. For ultralight bikepacking and light bike touring these sleeping bags are perfect.
- Ultralight sleeping bags from 600 grams to 799 grams: A very exciting sleeping bag weight class with great choice. Here you’ll find full three-season sleeping bags, which still provide warmth buffers even in low temperatures. If you want to spend less money, you will also find sleeping bag bargains in this weight category.
- Outdoor sleeping bags from 800 grams: If it is not primarily on the weight, but on maximum thermal performance and camping even at sub-zero temperatures depends, these sleeping bags are an option. The pack size is larger and the weight a bit higher, but in most situations you have a safety buffer as far as the temperature range is concerned. For winter camping in single-digit subzero temperatures, these sleeping bags are suitable.
The Outdoor Sleeping Bag Test is about ultralight sleeping bags for the seasons spring, summer and autumn. When selecting the sleeping bags, I mainly focused on quality, own experience and conscientious research. Alternative forms, such as Quilst, are considered in another article.
Top ultralight sleeping bag for 3 seasons
For starters, I’d like to introduce you to the Sea to Summit Spark SPII: an absolute top sleeping bag! I have this sleeping bag myself already several years in practice on tours in spring, summer and autumn. On the scale brings the SPII light 560 grams (size L with 198 cm).
- Aktivität: Bergsteigen, Trekking, Bergwandern
The comfort temperature is specified at 4 degrees Celsius: This makes it a true all-rounder! In warm weather, leave the zipper open and you have a light summer sleeping bag. Combined with a lightweight down jacket*, the Seat to Summit Spark SPII is perfectly adequate in early spring and late fall.
For completeness: The sleeping pad pictured above is the Sea to Summit Ultralight Mat.
The hydrophobic treatment of the down speaks for the versatility of the SPII: This makes it extremely resistant to moisture. Even in the rather cold and wet environment on Iceland the Spark SPII could convince. I also took the SP2 with me on a cycling tour in Denmark and in the Black Forest in autumn: Here, too, the ultra-light down sleeping bag was convincing all along the line!
With this inexpensive accessory you can upgrade your sleeping bag for the colder season:
You are looking for a cheap down sleeping bag for the rather warmer season? Then the Forclaz Trek 900 is a light and compact option.
The Forcalz Trek 900 down sleeping bag is available at Decathlon:
Outdoor Sleeping Bag Test
We will start with the ultralight sleeping bag test in a moment. Also check out the guide with the most important factors when buying ultralight sleeping bag. What should you look for to ensure your ultralight sleeping bag keeps you warm for most of the year?
Sleeping bags: 400 to 600 grams
The most flexible sleeping bag category: The Ultralight sleeping bags are suitable for nights in spring, summer and winter. Up to approx. 5 degrees one can spend the nights very comfortably in these sleeping bags. Combined with a light down jacket*, the temperature range is extended up to about 0 degrees. If you start camping in spring (April) or until autumn (October), you can extend the temperature range with a fleece inlay.
The temperature range is certainly just right for most people and perfectly adequate. In addition, you get the benefit of minimal pack size and light weight.
I am very enthusiastic about the Sea to Summit Spark SP2: I have been using the ultralight sleeping bag for several years and have since used it on tours in spring, summer and autumn. Whereby the summer is actually too warm 🙂 the sleeping bag is really light with only 560 grams (in size L to 198cm). In the laboratory, a comfort temperature of 4 degrees was determined. Exactly up to this temperature one also sleeps very pleasantly in the SP2. To save weight, the Seat to Summit Spark SPII is cut rather tight and has a half-length zipper – it’s an ultralight sleeping bag. In the small size M up to 185 cm it even weighs only slightly more than 500 grams. From me there is a very clear recommendation for the Sea to Summit Spark SPII!
Therm-a-Rest Hyperion 32 UL: Therm-a-Rest has with the Hyperion sleeping bags a range of ultralight sleeping bags in the offer. I find the Therm-a-Rest Hyperion 32 UL particularly interesting. With a weight of only 510 grams, it is definitely one of the really light ultralight sleeping bags and manages a usable comfort temperature of 0 degrees. This makes it suitable for a wide range of applications. With an inlay, as well as a small down jacket, comfortable nights should be doable even in spring and early winter.
Yeti Down Sleeping Bag Passion Three: The Yeti Down Sleeping Bag also weighs in at just 530 grams. This makes it one of the lightest ultralight sleeping bags in the comparison and is suitable for ultralight hiking and bikepacking. The Yeti Passion Three is specified with a limit temperature of 3 degrees. Thus, the Yeti Passion Three is to be understood as a limited three-season sleeping bag: In summer, the down sleeping bag can be used without restrictions. In early spring, as well as late autumn, it is recommended to use a light down jacket as an extra layer and a fleece inlay.
Western Mountaineering HighLite: The HighLite down sleeping bag offers light weight at a great price. It weighs only 480 grams and has a limit temperature of -1 degrees. This combination is really strong and worth a very close look.
Naturehike Ultralight Down Sleeping Bag: The price tip in this category is the ultralight sleeping bag from the Chinese manufacturer Naturehike. For little money, a lot is really offered here: 610 grams are on the scale and the limit temperature is 2 degrees. Thus, the thermal performance of the Naturehike sleeping bag is comparable on paper with more expensive ones. How the appropriate temperature ranges were determined is an open question. The outdoor sleeping bag has a straight cut. So you have a lot of space in the sleeping bag but there is also more air in the sleeping bag. This must be heated up by the own body heat. This means you probably lose a few degrees of warmth compared to more expensive sleeping bags. Considering the price-performance ratio, the Naturehike sleeping bag is a bargain. The origin of the down is still open. I requested a certificate from Naturehike.
Conclusion: Ultralight sleeping bags from 400 grams
The very clear recommendation is the Sea to Summit Spark SPII! The sleeping bag is not only small and light, but also incredibly versatile: The comfort temperature of 4 degrees is absolutely sufficient for most touring conditions from early spring to late autumn. The Sea to Summit SPII has been with me for many years on both hot and dry, as well as on cold and wet trips and I am always thrilled with this great sleeping bag.
The Sea to Summit SPII is an all-rounder that works for many conditions!
Sleeping bags: 600 to 800 grams
In this temperature range there is a wide selection of outdoor sleeping bags and ultralight sleeping bags. For the outdoor sleeping bag test, I researched five interesting models. The selection ranges from really warm, to ultra-light, to very inexpensive. As I said, the range in this category is very large.
Sleeping bags between 600 grams and 800 grams have a wide range of uses and can be used in combination with an inlay and a light down jacket* even on cold spring and fall nights.
Sea to Summit Spark SPIII: Versatile is the Sea to Summit SPIII. The comfort limit is 2 °C and the limit temperature is -8 °C. Despite the broadly applicable temperature spectrum, the Sea to Summit Spark SP3 still remains small and light. Thus, the lightweight sleeping bag is particularly suitable for bikepacking and hiking tours in cooler weather.
Robens Couloir 350: The Robens is a great and versatile sleeping bag with small weight and small pack size. It doesn’t quite match the warmth of other sleeping bags in this category, but it is significantly cheaper than comparable sleeping bags. Its temperature limit is -4 °C. By cleverly adding more layers of clothing, you can upgrade it to a fully-fledged 3-season sleeping bag.
Mountain Equipment Helium 250: A lightweight outdoor sleeping bag for summer and the warmer spring and fall months is the Helium 250 from Mountain Equipment. The comfort limit is 3 degrees and with approx. 680 grams the sleeping bag is pleasantly light. To make the Mountain Equipment sleeping bag slightly water repellent, a DWR impregnation is used.
Yeti Passion FIVE: A full three-season yet lightweight sleeping bag is the Yeti Passion FIVE. It weighs 790 grams and thanks to down with 800+ cumin density, the comfort temperature is -2°C and the comfort limit is -7°C. This should make comfortable nights possible even in spring and into autumn! With an inlet, the temperature range can be extended, as always. For bikepacking, bike touring and hiking, the Yeti Passion FIVE is worth a close look.
Decathlon Forclaz Trek 900 10 °C: Decathlon’s price tip has a small pack size and keeps you comfortably warm at 10 °C. The limit temperature is at 5 °C. This means that the Trek 900 can easily be used as a 2 – 3 season sleeping bag. In spring and autumn, it is additionally recommended to cleverly combine clothing layers and use an inlay. The down is not according to the RDS standard, but comes from ducks from meat production. You can’t guarantee that, but I think this statement at Decathlon is quite credible. The down itself does not seem to be treated against moisture. For this, the outer material is water-repellent. Sleeping in a damp environment should thus be quite loose possible. Compared to well-known brands, the Decathlon sleeping bag costs only a fraction. For this, you have to accept about 200 grams more weight. Overall a very exciting sleeping bag for bikepacking and hiking and the price recommendation.
Conclusion: Ultralight sleeping bags from 600 grams
There are many exciting sleeping bags in the 600 gram to 799 gram category! The most interesting ones are:
- Sea to Summit Spark SPIII: The SPIII variant of the popular Spark sleeping bag series. With a little more down filling, the Sea to Summit sleeping bag becomes even more versatile and can be used comfortably even in slightly sub-zero temperatures. A high priced sleeping bag where you get a lot of quality for your money.
- Decathlon Forclaz Trek 900 10 °C (price tip): The Deathlon down sleeping bag is particularly suitable for price-conscious bikepacking beginners. For many requirements this down sleeping bag is absolutely sufficient. Even if you’re going on tour in the summer and want a quality sleeping bag, the Decathlon Forclaz Trek 900 10 °C is an exciting choice. The technical values are convincing. I took a close look at the sleeping bag in a Decathlon store. The pack size is comparable to the Sea to Summit Spark SPIII and therefore absolutely suitable for bikepacking.
Sleeping bags: 800 grams to 1Kg
When weight is no longer the main focus, these sleeping bags are worth a close look. Application areas for these sleeping bags are e.g. bike trips or hiking. Also in winter sleeping bags of this category can definitely be used. Since these are outdoor sleeping bags rather than exclusively ultralight sleeping bags, some of the sleeping bags also offer more comfort through a wider cut, longer zippers, or zippers on both sides.
Sea to Summit Spark SP IV: If you want your sleeping bag to be really warm, the Spark SP4 is worth a close look. As with the entire Sea to Summit Spark series, hydrophobic i.e. particularly water-repellent down is also used in the Spark SP4. With a limit temperature of -15 °C, the Spark 4 can definitely be used as a full winter sleeping bag.
Vaude Rotstein 450 DWN: A 900 gram lightweight down sleeping bag with a limit temperature of °C degrees. A fully-fledged 3-season sleeping bag. Vaude attaches great importance to sustainability and therefore the Rotstein 450 DWN was produced according to the specifications of the Green Shape Label. Down obtained according to the Responsible Down Standard is also used. For added comfort, there is a two-sided zipper, a thermal collar and a hood on the sleeping bag.
Carinthia G 145: The Carinthia G 145 is one of the few synthetic fiber sleeping bags in the comparison. The overall package of price and performance is right with this sleeping bag. The weight of 820 grams remains within limits and is quite suitable for hiking and cycling trips. At 6 °C is the comfort temperature and at 1 °C the limit temperature. The temperature range is comparable to down sleeping bags, which weigh about 200 grams less. The Carinthia G 145 is suitable for camping in warm spring and autumn temperatures. If it does get a little colder, an inlay and a thin down jacket will help. Then outdoor nights at slightly sub-zero temperatures should be possible (range of use: April to October).
YETI Tension Comfort 300 +3: YETI sleeping bags are sleeping bags Made in Germany. The Tension Comfort is cut slightly wider than typical ultralight sleeping bags. Of course, more material has some effect on the weight: 3 °C is the limit temperature at a weight of 840 grams. With these values, the YETI Tension Comfort 300 +3 can be considered a 2 – 3 season sleeping bag.
Decathlon Forclaz Trek 900 0 °C: Decathlon currently offers two down sleeping bags. The Trek 900 0 °C is the warmer variant for nights up to around the freezing point (limit temperature 0 °C). For bike trips and hiking tours, the Decathlon sleeping bag is suitable given the weight and pack size. The outer material is water-repellent, a hood, warmth collar, as well as a two-way zipper are available. The Decathlon sleeping bag has similar features to many more expensive sleeping bags. But it weighs about 200 grams more. As a price-performance tip, the Decathlon sleeping bag is an exciting choice.
Conclusion: Outdoor sleeping bags from 800 grams
Also the category of down sleeping bags and synthetic sleeping bags from 800 grams is again very exciting! Here is again a large selection of suitable sleeping bags for the cold season.
Sea to Summit Spark IV: The Sea to Summit down sleeping bag from the Spark series, is also available with extra down filling quality 850+ Quin. With a comfort temperature of -8 degrees Celsius, the sleeping bag is also suitable for winter camping. By cleverly combining additional layers of clothing, you should be able to sleep comfortably even in light double-digit sub-zero temperatures.
Decathlon Forclaz Trek 900 0 °C (price tip): The price tip is again the Decathlon down sleeping bag. For a small price you get a lot of thermal performance here. The comfort temperature is 0 degrees, making the Trek 900 0 °C a full three-season sleeping bag.
If it should be synthetic fiber, then the Carinthia G 145 is an inexpensive and right warm synthetic fiber sleeping bag.
Advisor – what to look for when buying?
What should you look for when buying an ultralight sleeping bag?
Weight & Pack size (or compactness)
Lightweight sleeping bags weigh very little. The weight logically determines other factors such as the volume and the appropriate temperature range.
The lightest and smallest sleeping bag will do you no good if you freeze in it. Therefore, the temperature range must also fit your intended use.
When it comes to temperature range, there are three important specs, which you always hear and read about. These are indicated in the product information of each sleeping bag. Let me explain what they mean:
- Comfort range (TCom): At this temperature the sleeping bag keeps comfortably warm
- lower limit range (TLim): Sufficient protection is still offered at this temperature
- Survival range/extreme range (TExt): Danger of hypothermia exists above this limit.
You know the approximate temperatures at night for your adventures? Your outdoor sleeping bag should be designed for this comfort range (TCom).
Material: down or synthetic fibre?
Down sleeping bag or synthetic fibre sleeping bag? Let’s look at the advantages and disadvantages. Which sleeping bag is less harmful to the environment? The choice of the filling is on the one hand an ethical question, on the other hand there are tangible advantages and disadvantages.
A down sleeping bag has the best warmth to weight ratio. The pack size is smaller because down compresses more. However, a down sleeping bag is more expensive to buy and wants to be treated with care. A down sleeping bag is very durable: properly treated, a down sleeping bag can have a lifetime of 10 years and more. In addition, a down sleeping bag should not get wet. When wet, down loses much of its thermal performance and it takes a long time for down to dry.
Nowadays, modern materials strongly counteract this disadvantage:
- Pertex Quantum outer material
- Hydrophobic down & impregnations
This means that even in humid areas you are very well positioned with a down sleeping bag these days. The disadvantage is the high purchase price. Also, non-ethical production of down cannot be completely ruled out, more on this below.
✅ Very light
✅ Good compression: thus smaller pack size possible
Best weight to thermal performance ratio
✅ Who keeps its insulating capacity for a very long time, if stored correctly
❌ More expensive than synthetic fiber
❌ Thermal performance drops sharply when wet
❌ Dries slowly
❌ Unethical extraction of down cannot be completely ruled out
❌ More expensive to maintain
A synthetic sleeping bag is larger and heavier than a down sleeping bag. Since synthetic fibers have worse insulation than down, more material must be used. Examples of modern synthetic fibres are e.g. Primaloft. Almost all of the insulation is retained when wet, and a synthetic sleeping bag is easier to care for. Also, a synthetic sleeping bag is cheaper to purchase.
✅ Cheaper to buy
✅ Better thermal performance when the sleeping bag is damp
✅ Simple in care
✅ Dries quickly
✅ Good thermal performance with appropriate filling quantity
Heavier than a down sleeping bag, as more filling is required for the same warmth.
❌ Not as compressible as down: therefore larger pack size
❌ Lower service life
Environment & Ethical aspect: Down is obtained from ducks and geese. But how are the animals treated? Is the extraction of the down done as dead pluck or live pluck? In the case of dead plucking, the down extraction is a by-product of the meat industry. In live plucking, the feathers are plucked from the animals while they are still alive. This is very painful for the animals. Many manufacturers have own seals, which are supposed to attest to the ethical extraction of the down. There is also the RDS (Responsible Down Standard) seal, that you can look out for.
Plastic fiber sleeping bags are also not completely harmless: In the production of synthetic fibers, large amounts of chemicals are produced. If a down sleeping bag loses a down, then this is not bad for nature. With the synthetic fiber sleeping bag, on the other hand, plastic is distributed in nature in this case, which is problematic.
Neither a synthetic fiber nor a down sleeping bag is ethically and for nature completely unquestionable. It is therefore all the more important that you find the right sleeping bag for you. Then you can use it as long as possible and have a lot of fun with it. This creates the smallest footprint for nature and animals.
Find the right size
Sleeping bag models are almost always available in several sizes.
Which sleeping bag size suits you best? In practice, the sleeping bag should be slightly larger than your body size. Manufacturers also often specify a from to a minimum and maximum body size for their for the sleeping bag. If the manufacturer does not specify from-to, a sleep size of body size + 10 centimeters is a good guide. You then usually have just the right amount of space at the foot end and can cover up your upper body comfortably.
In a sleeping bag of the right size you can sleep comfortably and have the optimal insulation performance. If the sleeping bag has a hood, it fits exactly on your head.
If your sleeping bag is too big, there will be a lot of empty space between your body and the sleeping bag. You have to warm these up with your body heat, wasting valuable energy.
A sleeping bag that is too narrow or short will usually touch you mainly in the foot area, or the sleeping bag will be too short on your upper body. Not only is this uncomfortable and you lose energy by not covering your upper body, but you compress the material of the sleeping bag by touching it. At the contact points then cold bridges. Exactly at these places you will freeze first.
Ultralight sleeping system
Your ultralight sleeping system consists of your mattress, your tent and your sleeping bag.
- Reading tip: Ultralight sleeping pads in the big practical test.
- Reading tip: The best tents for bike travel and for bikepacking in the test & comparison.
Increase the thermal performance of the sleeping bag
When buying an outdoor sleeping bag, you often decide on a certain temperature range. Do you want an ultralight sleeping bag for three seasons (spring – autumn) or do you also want to camp with the sleeping bag in winter?
The temperature range of your sleeping bag can be cleverly extended with additional clothing layers and an inner sleeping bag. A small and light three-season sleeping bag, can then also be used in slightly sub-zero temperatures. Your sleeping bag then has a really wide range of uses.
Increase heat output with inlay
To increase warmth, an inlay is placed inside your sleeping bag. An inlay is therefore an inner sleeping bag. Inlays are a cheap solution and you can increase the warmth of your sleeping bag by a few degrees. Manufacturers sometimes promise a gain in heat of up to 20°. In practice, a good inlay increases the heat output by approx. 5 degrees to 8 degrees.
Increase thermal performance through additional layers
Extra layers of clothing are also great for using your sleeping bag in colder temperatures. You can combine the additional layers of clothing in the onion principle and thus get even more warmth.
Particularly long underwear or tight-fitting tops made of merino wool bring again extra warmth. The natural product merino wool has an excellent thermal performance, is breathable and hardly smells.
Recommended Merino Wool Products:
You lose most of your energy through your head and you can’t sleep with cold feet. Here, too, a multi-functional scarf or and merino wool socks are suitable. This allows heat loss to be reduced to a minimum. The multifunctional scarf also serves as a sleeping mask 😉
Recommended multifunctional scarf and warm merino wool socks for the tent:
- Multifunctional scarf
- Merino wool socks*
Lying freezing in an ultra-light sleeping bag and placing the cosy down jacket next to it makes no sense! You can plan your down jacket as an additional and most importantly fixed component of your sleeping system. If it gets cold at night, just put on your down jacket in your sleeping bag. This gives you an additional few degrees of warmth.
Recommended down jacket:
Conclusion: Ultralight sleeping bag and ultralight sleeping system
Now you know what to look for when buying an ultralight sleeping bag. You know the different materials with their advantages and disadvantages. You also got an overview of interesting outdoor sleeping bags and know a recommendation from practice!
Are all your questions answered? Do you have an opinion on the topic or still have individual questions? Drop me a comment and I’ll be happy to respond.
For your ultralight sleeping system, are you still looking for the ideal tent for bikepacking and bike touring or are you looking for an ultralight sleeping pad. Best check out the linked guide articles.