Kart.no guide
How to choose the right sleeping bag
Choosing the right sleeping bag is primarily about temperature, intended use, insulation and fit. A lightweight summer sleeping bag and a warm winter sleeping bag serve very different purposes – and the most expensive model is not necessarily the right one for your trips.
What will you use the sleeping bag for?
Start with the trips you actually plan to take. If the sleeping bag will mainly be used for camping, festivals or warm summer nights, an affordable synthetic model may be more than sufficient.
If, on the other hand, you will carry the sleeping bag over longer distances, use it across several seasons or sleep outdoors when temperatures drop well below freezing, temperature rating, insulation, weight, packed size and fit become much more important.
A sleeping bag that stays in the car on a camping trip does not necessarily need to weigh 500 grams or pack down to just a few litres. On a multi-day hike with everything on your back, those characteristics can be well worth paying more for.
Price is not only about how warm a sleeping bag is. You often also pay for lower weight, a smaller packed size, more advanced materials and a construction that provides a high level of insulation relative to its weight.
Down or synthetic sleeping bag – which should you choose?
Both down and synthetic insulation can keep you warm. The main differences are weight, packed size, moisture management, price and intended use.
Synthetic sleeping bag
Down sleeping bag
What do 700 cuin, 800 cuin and 90/10 mean?
On down sleeping bags, 90/10 describes the ratio of down to feathers. Fill power, stated in cuin, describes how much volume a given amount of down can create. A higher fill power makes it possible to achieve effective insulation at a relatively low weight.
However, a higher cuin value does not automatically mean a warmer sleeping bag. You also need to consider how much down is used and how the sleeping bag as a whole is constructed.
Three useful figures when comparing down
Down meets wool
What is DownWool®?
Grüezi Bag DownWool® 2.0 combines 70% down and 30% wool. The down provides much of the lightweight and efficient insulation, while the wool helps regulate temperature and moisture inside the sleeping bag.
This can be particularly useful when temperatures vary during the night or the body releases a lot of moisture. The aim is not only effective insulation, but also a more stable and comfortable sleep climate.
How warm a sleeping bag do you need?
Start with the lowest temperature you realistically expect to encounter, and allow some safety margin – especially if you know that you tend to feel cold.
On temperature-tested adult sleeping bags you will usually find T Comfort, T Limit and T Extreme.
The safest starting point for most people when deciding how warm their sleeping bag should be.
A lower standardised temperature limit. It is not the same as normal comfort.
An extreme limit related to risk and survival – not a temperature you should plan around.
For most people, T Comfort is the best basis for comparison. Do not choose a sleeping bag based on T Extreme.
Some manufacturers also specify their own recommended practical temperature range. This can be useful alongside standardised EN ISO values, but the two types of temperature rating should not be confused.
How warm you actually feel is also affected by factors such as your sleeping mat, wind, humidity, clothing, food intake and individual tolerance to cold.
Summer, three-season or winter sleeping bag?
Seasonal categories are a practical way to narrow down the options, but the temperature ratings tell you more than the category name itself.
Summer sleeping bags
Lightweight sleeping bags for warm nights, summer use, travel and milder conditions.
Three-season sleeping bags
For many people, the most versatile option for spring, summer and autumn.
Expedition and winter sleeping bags
More insulation and constructions designed for cold conditions and temperatures below freezing.
Size and fit – how much room do you need?
Your sleeping bag should give you enough room to lie naturally and move without pressing against the insulation. A bag that is too short or tight can compress the insulation and reduce its loft.
If you are right on the boundary between two sizes, we normally recommend choosing the larger one. A little extra length is usually much less of a problem than a sleeping bag that is too short.
Also consider the width. Enough room around the shoulders, hips and feet makes it easier to turn inside the sleeping bag and helps the insulation retain its loft.
We explain body height, sleeping bag length, width, size limits and why a little extra length is usually better than a bag that is too short.
How important are weight and packed size?
At a campsite it may make little difference whether your sleeping bag weighs 1.5 kilograms and takes up 12 litres. On a week-long mountain hike, the difference between 1.5 kilograms and 700 grams can be very noticeable.
If the sleeping bag will be carried far and often, the balance between warmth, weight and packed size is therefore important. But do not compare weight alone.
Two sleeping bags with the same temperature rating may have slightly different weights because one is longer or wider. A difference of 50–100 grams does not necessarily mean that the lighter model is technically better – some of the weight may simply come from more usable space around the body.
Your sleeping mat is part of the insulation system
When you lie in a sleeping bag, the insulation beneath your body is compressed and insulates less effectively against the ground. The sleeping mat therefore provides most of the protection against heat loss downwards.
Your sleeping bag and sleeping mat should therefore be considered as one system, especially as temperatures fall.
The sleeping bag insulates around your body
Loft traps warm air, but the insulation beneath your body is compressed when you lie on it.
R-value describes the insulation of the sleeping mat
In cold conditions, you should therefore check the R-value of your sleeping mat – not only the sleeping bag’s temperature rating.
An example of an insulated sleeping mat for hiking, with an R-value of 3.9, integrated down and wool insulation and a weight of approximately 750 grams.
Can you make a sleeping bag warmer?
Yes. A sleeping bag liner or insulating sleeping bag warmer can extend its usable range, and two compatible sleeping bags can also be combined. According to the manufacturer, the Grüezi Bag Schlafsackwärmer can increase warmth by up to 10 °C, depending on the combination and conditions. Extra insulation is still no substitute for a proper winter sleeping bag when conditions become genuinely cold.
Sleeping bags for children and teenagers
The temperature standard used for adult sleeping bags cannot simply be used to specify equivalent temperature limits for children. An adjustable children’s sleeping bag can reduce unnecessary empty space when the child is small and be extended as they grow. For teenagers approaching adult height, an adult model with some room for growth can be a natural choice.
Store your sleeping bag loosely
Dry and air your sleeping bag thoroughly after a trip. Avoid storing it permanently under heavy compression – the compression sack is primarily intended for transport. For long-term storage, keep the bag loose in a larger storage sack or hang it uncompressed. Always follow the manufacturer’s washing instructions.
Which sleeping bag should you choose?
Start with where you will sleep and how cold it can realistically get. Then choose insulation, size and weight according to how the sleeping bag will be used. Camping places different demands on your equipment than a long mountain hike, and winter use requires something different from warm summer nights.
Do not focus on a single specification. Temperature, fit, weight, packed size and sleeping mat should be considered together. Once you know which of these factors matter most for your trips, choosing the right sleeping bag becomes much easier.