How Much Warmth Does A Sleeping Bag Liner Add?

If you enjoy camping and use a sleeping bag, you may need to know the benefits a sleeping bag liner provides for you.

One question many tenters have when thinking about one of these liners is, does a sleeping bag liner add warmth and how much? A sleeping bag liner can add anywhere from 5° F to 25° F of extra warmth to a sleeping bag. Different levels of warmth depends on the material they are made.

You can see in the table below how much warmth does a sleeping bag liner add to your sleeping bag by material variety:

Type	Added Warmth
Silk Liner	+5° F
Cotton Liner	+5° F
Microfiber Liner	+5°F to +10°F
Merino Wool Liner	+5°F to +10°F
Fleece, Microfleece Liner	+12° F
Insulated Liner	+25° F
Thermal Synthetic Liner	+25° F

Which Sleeping Bag Liners Add the Most Warmth?

Sleeping bag liners come in a variety of materials. Which liner you choose will depend on the type of camping you prefer. The fleece and microfleece liner add up to twelve degrees Fahrenheit to your sleeping bag.

These liners will add a bit more to the weight you’ll have to carry into your campsite. If you are looking for more than twelve degrees to add to your heat source, there are also insulated sleeping bag liners.

The insulated sleeping bag liners can add up to twenty-five degrees Fahrenheit to your night-time comfort. The down-side to adding heat to your sleep, they also add weight to your camping gear.

If weight is more a concern than heat, there are other liners you can use in your sleeping bag.

• The silk liner adds about 5 degrees to your sleeping bag’s warmth level. The added warmth from the silk liner is a bonus as these liners are designed more to keep your bag clean. Silk bag liners add softness and are one of the most lightweight materials you could choose and will add only about 200 grams to your gear.
• Cotton liners will give you about 5 degrees of warmth, as well. These liners are a bit bulkier and will add to packing and carrying issues with your gear. The cotton liner will also not wick away moisture or breathe as well as the silk choice. This material is the most popular choice by tenters, however, as it costs less and is a more durable material. It only adds about 300 grams to the weight of your gear.
• Microfiber increases the added warmth over the cotton, by giving you from 5 to 10 degrees of additional warmth. It is a very comfortable material and could help you sleep more comfortably.
• Merino wool will also add 5 to 10 degrees of warmth to your sleeping bag. It is also very soft and will wick away moisture. This material is on the more expensive end of liners. 
• Thermal synthetic adds even more warmth. With a thermal synthetic sleeping liner, you will get up to 25 degrees added warmth to your sleeping bag. Thermolite fabric works so well as it has hollow-core fibers that are able to trap air. These not only add more heat to your sleeping bag, but they are also a lightweight insulator. 

Do You Need a Sleeping Bag Liner?

The first reason most tenters look for a sleeping bag liner is to add warmth to their sleeping bag. If you use your car to camp and are able to pull right up to your campsite, you don’t have to worry as much about the weight or bulk of a sleeping bag liner.

If you are a hiker who carries your gear for a distance before setting up, you will want to go with a lighter weight liner if you choose to use one at all. The added warmth is not the only benefit you get from a sleeping bag liner.

Before you decide whether or not you want to add one to your camping gear, look at some of the advantages:

• Keep the sleeping bag cleaner and prolong its life. With a liner in your sleeping bag, it will prevent oils and sweat from getting on or into your sleeping bag. Without the liner, all dirt gets into the sleeping bag, and it will lose its effectiveness. If you have a down sleeping bag, a liner will prevent your sweat from ruining the down material. Your bag will last longer and keep you warmer. 
• The sleeping bag liner is much easier to wash than a sleeping bag. It will also increase the life of your sleeping bag as washing a sleeping bag too often will wear it out.
• You can use the liner by itself when the weather gets warm. If you are camping where the temperatures can get warm, you can use your sleeping bag as a pad and sleep inside the liner. 

Sleeping bag liners are much like the sheets you put on your bed. The sheets protect the blankets and bedspread from dirt and oils from your skin. The liner works in the same way to protect your sleeping bag. The liners can also help keep crawling bugs off you during your sleep.

So, there are a lot of benefits to using a sleeping bag liner, but do you have to use one? The answer to that would be no. They do add warmth to your sleeping bag, but there are other ways to stay warm when you’re tenting or camping.

The first thing is to make sure you have a good sleep system. Having a good sleep system means having an appropriately rated sleeping bag that will provide you with good ground insulation. You can also double up or get a thicker sleeping pad.

Another factor to consider to help you stay warm while tenting is to wear clean clothing. After you’ve spent the day discovering the sites, change into a set of fresh, dry clothes before crawling into your sleeping bag.

Dry, warm clothes will help keep you warm and make you feel better. When clothes get damp, they are going to rob your body of heat.

There is a lot of debate regarding whether or not tenters or campers should use sleeping bag liners. Some firmly believe in them and would not set out with their sleeping bag without a liner. Others feel they are unnecessary and only add to an already long list of gear that is essential to carry into the campsite.

The bottom line is the sleeping bag liner is not necessary; however, they are nice to have and do offer a lot of advantages.