What is considered a light sleeping bag? 

What is considered a light sleeping bag? 
by wayhomestudio - www.freepik.com

There are a variety of sleeping bags available in the market filled with different materials to provide you with warmth in different conditions. Though there are plenty of blogs or information on the web about ultralight or light sleeping bags, but no one tells what is a weight scale makes a sleeping bag light or heavy sleeping bag. If you ever wonder, the sleeping bag you have is light enough to take on a hike then don’t worry today I will tell you what is considered a light sleeping bag? 

What is considered a light sleeping bag? 

A sleeping bag that is below 1lb is considered an ultralight sleeping bag while the sleeping bag which weighs more than 1lb but is less than 4lb is considered a lightweight sleeping bag. Any sleeping bag that surpasses 4 lb is usually considered a not heavy but slightly heavy sleeping bag for a backpack

What makes a sleeping bag light or ultralight? 

There are various reasons why some sleeping bags are lighter than others. The most important is the material used in the bag, the second is how the shape of the bag. First, let’s start with the material that makes the sleeping bag light.


There are different types of materials used in making a sleeping bag and each material suits the different conditions and different weather. 

The fill material in most of the light and ultralight sleeping bags is down. Down is expensive and comfortable material. Moreover, it’s light in weight and it’s easy to pack them in a backpack. 

Another most common material used is synthetic. Synthetic is used in sleeping bags because they retain heat and wet much better than down, but are heavier. You will find sleeping bags filled with synthetic material cheaper and bulkier than down-filled bags. 

Other than down there are other natural fillers that are used in sleeping bags such as cotton and wool. But the main difference between all three is that wool is heavy and makes the sleeping bag heavy and difficult to carry while hiking mountains. On the other hand, cotton also gets heavy because of its open pores which can carry more water. Though wools are heavy but surely provide more warmth in cold conditions but you can carry wool insulated bags for a long if you are hiking. On the other hand, cotton sleeping bags are an inexpensive and a great option for indoor campaigning.  

Of all the materials that are discussed above, down is the lightest, expensive, and comfortable material used in sleeping bags for insulation.

The clusters in down are able to create around hundreds of tiny pockets. These pockets allow the air to trap inside and then our body heat warms up that air this provides is warmth in return. 

The fill volume in sleeping bag is also the factor that decides the weight of the sleeping bag. The light sleeping bag will have high fill power than heavy sleeping bag fill power. Mostly the sleeping bags that are ultralight have higher down fill power. 

The last factor that makes the sleeping bags light is the shape of the sleeping bags. Yes, this may be unknown to many but shape plays important role in the weight of the bag. 

The purpose of a sleeping bag is to provide warmth inside a small space. The more the space the more time it takes to warm up the sleeping bag and furthermore space also adds weight to the sleeping bag. 


There are four different shapes options provided in the sleeping bag – rectangular, double, mummy, semi-rectangular. 

Mummy- mummy shape sleeping bags are small in size which also means they are can warm up inside fast than other shapes. Moreover, because of its small size, the weight of the bag will also decrease. But, while we are making comparisons between different shapes make sure we are only talking about one material. Different materials in different shapes will weigh differently and don’t forget the factor of filling. 

Semi rectangular-  it’s a little bit same as a mummy but an upgraded version which provides you more space. This also provides you more comfort. 

Double- double sleeping bags are big and wide sleeping bags with a lot of space inside for two-person. These are basically for couples who can sleep in one sleeping bag. These provide you space and comfort but can easily get warm if two persons are inside. However, the weight of the double sleeping bags is more than mummy-shaped sleeping bags. 

Rectangular- These types of sleeping bags are common and standard in the industry. These are for a single person and gives you more space and a comfortable experience than mummy shape sleeping bags.

More on sleeping bags

Let’s take the example of two sleeping bags to know what makes one sleeping bag heavy and the other one light. 

Western Mountaineering Alpinlite 20° and REI Co-op Trailbreak 30 are two different sleeping bags that weigh different. Alpine 20° weighs around 1.2 lb while the Tarilbreaj 30 is heavy and weighs around 2.5 lb. So why is tailback heavier than Alpinlite? The first is the insulating material. The material used for insulation in Alpinlite is down while trailbreak is filled with synthetic material. Moreover, the bulkiness of trailbreak 30 is more than Alpinlite which means it is difficult to pack it in a small space. Because of the material, the warmth is also more in Alpinlite. But it doesn’t mean that synthetic is no good. From both sleeping bags, the insulating properties of tarilbreak is more when wet than Alpinlite.

Though both sleeping bags are considered good for Backpacking still down insulated bags are more reliable and good, especially on long hikes. The main difference you will see in both the sleeping bags is price, the price of Alpinlite is somewhere near $570 while the trailback only costs you $99. However, the cheap deal is not always a good deal.$570 may seem more today but if you keep the sleeping bag, it may last you decades or more. 

Does light sleeping bags give you more warmth? 

Well, the warmth of the sleeping bag depends on the material used in it for insulation. Goose down is considered the warmest and lightest material for the sleeping bag. However, there are fillers like wool which are heavy than down natural filler but also have the ability to tackle the cold winter days. So, the main factor is not the weight of the sleeping bag that decides the warmth but the fillers. 

Conclusion- So, at the last, the light sleeping bags are basically those which weigh less than 2 lb, but there are now ultralight sleeping bags available in the market that provide you durability, best weight to warmth ratio. If you ever decide to buy a new sleeping bag then I would suggest you buy the light sleeping bag with down insulation if you are a hiker or one who travels a lot in different weather conditions.