How Sleeping Bag Temperature Ratings Work



When it comes to picking the right sleeping bag, temperature rating is one of the most important factors to consider. But how do those ratings work? Here’s a quick primer on how sleeping bag temperature ratings work and what they mean for your camping trips.

Sleeping bags are typically rated by their lowest comfortable temperature – that is, the temperature at which you can expect to stay warm and comfortable throughout the night. However, it’s important to remember that these ratings are only estimates, and your own comfort level may vary depending on factors like body type, metabolism, and clothing worn.


How Do Sleeping Bag Temperature Ratings Work?

When you’re shopping for a sleeping bag, one of the most important factors to consider is the temperature rating. But how do manufacturers come up with these ratings? In this post, we’ll explore how sleeping bag temperature ratings work and what they mean for your camping trip.

Most importantly, remember that the temperature rating is just a guide. Everyone sleeps differently and will feel warmer or cooler at different temperatures. Use the rating as a starting point to find the right bag for your needs.

Sleeping bags are usually rated using two different scales: the EN (European Norm) scale and the ISO (International Organization for Standardization) scale. The EN scale is more stringent, so a bag that’s rated -5°C on the EN scale will also be warm at -7°C on the ISO scale. The way manufacturers test their bags has changed over time, but today most use what’s called a thermal manikin.

This machine is designed to mimic human body heat loss and provides accurate results. Manufacturers place their bags in a cold chamber and lower the temperature until the manikin reaches an equilibrium point (this is when it loses as much heat as it produces). At this point, they record the temperature inside the bag.

That’s their official rating! Of course, there are other factors to consider when choosing a sleeping bag besides just the temperature rating. The type of insulation (down or synthetic), shell material, and weight all play a role in how warm your bag will be.

But if you use the manufacturer’s temperature rating as a guide, you’ll be sure to find a great sleeping bag for your next camping trip!

Sleeping Bag Temperature Ratings Explained

When it comes to choosing a sleeping bag, temperature rating is an important consideration. But what do those ratings actually mean? Here’s a breakdown of how sleeping bag temperature ratings are determined, so you can make sure you choose the right one for your needs.

Sleeping bags are designed to keep you warm in a variety of conditions, from hot summer nights to cold winter camping trips. The first step in finding the right sleeping bag is to determine the minimum temperature you’ll need it to be rated for. This will vary depending on your personal comfort level, as well as any other factors like whether you’ll be using a tent or other shelter.

Once you know the minimum temperature rating you need, take a look at how that number is determined. Temperature ratings are usually given in two ways: EN (European Norm) and ISO (International Organization for Standardization). Both systems use different methods to determine a bag’s warmth, so it’s important to know how each one works.

The EN system uses three different categories to rate bags: upper limit, comfort limit, and extreme limit. The upper limit is the highest temperature at which a person can sleep comfortably without sweating excessively. The comfort limit is the lowest temperature at which someone can sleep comfortably for eight hours without waking up due to being too cold.

And finally, the extreme limit is the absolute lowest temperature at which someone could survive for six hours without serious health consequences. ISO uses similar terminology but with slightly different temperatures. For example, their “comfort” range would be considered our “upper” range here in North America .

It’s important to note that these ranges are based on averages – everyone sleeps differently and will have their own ideal temperatures! – so don’t hesitate to adjust accordingly based on your own preferences and experience level . Now that you understand how sleeping bagtemperature ratings are determined ,you can be confident in choosing the right one for your next adventure!

How Sleeping Bag Temperature Ratings Work


What is a Good Temperature Rating for a Sleeping Bag?

Most people feel comfortable sleeping in a temperature range of 55 to 75 degrees Fahrenheit. However, this range can vary depending on your age, metabolism, and what you’re wearing to bed. If you tend to get cold easily, err on the warmer side.

And if you sleep hot, aim for the cooler end of the spectrum. Ultimately, you should choose a sleeping bag with a temperature rating that will keep you comfortable in the conditions where you’ll be using it most.

What Does a 30 Degree Sleeping Bag Mean?

When you’re shopping for a sleeping bag, one of the most important considerations is the temperature rating. This tells you the lowest temperature at which the bag will keep you comfortable. A 30 degree sleeping bag means that it’s designed to keep you comfortable at temperatures as low as 30 degrees Fahrenheit.

If you’re planning on doing any camping or backpacking in cold weather, a 30 degree sleeping bag is a good choice. It’ll give you some extra warmth in case the temperatures drop during the night. Just make sure to pair it with a warm sleeping pad and some cozy clothes, and you’ll be good to go!

What Temperature is a 3-Season Sleeping Bag?

Most three-season sleeping bags have an temperature rating between 10 and 20 degrees Fahrenheit. This means that they are designed to keep you comfortable in temperatures as low as 10 degrees, but will also provide some warmth in temperatures as high as 20 degrees. However, it is important to remember that these are only guidelines – everyone experiences temperature differently, so you may find that you need a different bag depending on how cold you get at night.

What Do the Numbers Mean on a Sleeping Bag?

The numbers on a sleeping bag represent the temperature range that the bag is meant to be comfortable in. The first number is the lowest temperature that the bag will keep you warm in, while the second number is the highest temperature it can withstand before becoming too hot. Sleeping bags are typically given a “comfort” and “limit” rating, with comfort being about 20 degrees warmer than the limit.

For example, a sleeping bag rated at +20/-10 would be intended for use in temperatures between 10 and 30 degrees Fahrenheit.


Sleeping bag temperature ratings can be confusing. Basically, the temperature rating is the lowest temperature at which the bag will keep you comfortable. But there are a few things to consider when looking at a bag’s temperature rating.

First, everyone sleeps differently and has different metabolism rates, so a bag that is comfortable for one person might not be as warm for another. Second, what you wear to bed makes a difference. If you’re wearing thermals or extra layers, you’ll be able to sleep in a cooler bag than if you’re just in your underwear.

Finally, your sleeping pad matters too. A good insulated sleeping pad will add warmth by reflecting your body heat back up at you; a cheap foam pad will do very little to keep you warm. When in doubt, err on the side of caution and get a warmer bag; it’s easier to unzip and cool down than it is to try to warm up in a too-cold bag!

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