What is R-Value in Camping Mattresses

If you’re shopping for a camping mattress, chances are you’ve stumbled upon the phrase “R-value” once or twice. We’ll dive into this topic below, but here’s the basic definition: R-value is a measurement of thermal resistance. Sleeping pads with lower R-values are more susceptible to heat loss, while those with higher R-values are better insulated and keep campers warmer on cold winter nights. 

This number can be confusing, but R-value is important to keep in mind when choosing a camping mattress or a sleeping pad–especially if you’re hoping to camp in cold weather or hang out in ski resort parking lots this winter. 

In this quick, informative guide, we’ll break down everything you need to know about R-value, including what R-value stands for, how R-value is calculated, what R-values are best for winter camping, and more. We’ll also recommend a couple of our favorite mattresses for cold-weather adventures.

Why do insulated sleeping pads matter?

Before we dive into all things R-value, we’d like to address a common misconception about camping mattresses. Many campers are unconcerned with mattress insulation, usually because they’ve already invested in warm sleeping bags. If you have a warm sleeping bag, why bother with an insulated mattress? 

To answer this question, it’s important to consider exactly how a sleeping bag keeps you warm. Sleeping bags trap warm air in pockets formed by the insulation inside the bag, and those pockets of warm air keep you warm. When you lie down on your sleeping bag, those air pockets are pancaked between your body and mattress and rendered useless. Not to mention, the ground is a major cold source while camping, one capable of leeching your body heat through the warmest of sleeping bags. It’s up to your mattress’ insulation, then, to keep the parts of your body that are in contact with the mattress warm. 

What is R-value?

The “R” in “R-value” might as well stand for “Relax” or “Rest,” because on a cold winter night, a higher R-value will help you do just that. In reality, though, the “R” stands for “Resistance.” 

R-value, as we mentioned earlier, is a measurement of thermal resistance, and it denotes how well a material resists heat flow or heat transfer. The higher the R-value, the more resistant the material is to thermic conduction. In other words, mattresses with higher R-values are less susceptible to heat loss and are thus warmer and better suited to camping in the cold.

While we focus specifically on sleeping pads and mattresses in this article, R-value is also used to describe everything from, as Lil Jon once yelled, the windows to the walls. That’s right–if you walk through the aisles of Home Depot, you’ll see everything from triple-pane windows to thick foam insulation boards that boast high R-values.

How is R-value calculated and tested? 

In the past, different sleeping pad brands had different R-value testing techniques, which made shopping for the right sleeping pad extremely difficult. Nowadays, most gear manufacturers stick to the ASTM F3340-18 standard testing method, which is helpful, as it allows campers to more accurately compare different products from different brands. 

This standardized R-value test involves placing a sleeping pad between a cold metal plate and a hot metal plate in a lab setting. The cold plate mimics the ground, while the hot plate represents your body’s natural warmth. This setup allows lab workers to measure the temperature exchange between the two plates and provide a standardized R-value. 

This is a fairly simplistic overview of R-value testing, but if you’d like to learn more or watch this test in action, check out this video from REI on the subject.

What R-value is right for me? 

While R-value is a now-standard measurement of sleeping pad thermal resistance, there are a few factors that can make picking the right R-value challenging. Wind and precipitation can impact your warmth, and the same goes for your sleep setup. Are you bunking down in a tent or sleeping under the stars? Are you camping in a vehicle? All of these pieces of the puzzle influence what R-value is right for you. 

That said, general consensus is the following: 

• R0 - R2: Best reserved for summer use
• R2 - R4: Suitable for three-season use
• R4 - R6: Suitable for winter use
• R6+: Ready for extreme cold

Before we share a couple of our favorite mattresses for cold-weather camping, here are a few things to note:

• Different mattress types can have the same R-value: Mattress type can dictate R-value. For example, air mattresses tend to have lower R-values than hybrid or foam mattresses. However, you can have a hybrid mattress with an R-value of 2, and a foam mattress with an R-value of 2, and they will provide the exact same amount of insulation. 
  
  
• R-value is additive: If you have two R2 mattresses and stack them, your new Franken-mattress has an R-value of 4. For this reason, you’ll often see winter campers and mountaineers use a closed-cell foam pad with an inflatable mattress on top. 
  
  
• Higher R-values won’t make you overheat in the summer: We camp on mattresses with high R-values all summer long and don’t have any issues with overheating. Yes, well-insulated mattresses are warmer in colder temperatures, but they won’t make you overheat in the summer like a warm sleeping bag will. In warmer temperatures, we’ll adjust accordingly by ditching the sleeping bag and keeping it simple with a set of sheets, and if needed, a light blanket.

Say Hello to AIR+FOAM PRO: Our Favorite Mattresses For Cold-Weather Camping

A camping mattress has two jobs. The first is to keep you warm, as we’ve discussed at length already. The second? To keep you comfortable, so you can sleep like a rock and wake up refreshed and energized for a day of adventures. Our newly launched, unbelievably comfortable AIR+FOAM PRO Mattresses do just that thanks to a thick, plush, insulative, and ultra-comfy open-cell foam construction. You can even inflate or deflate the mattresses to fine-tune the firmness to your liking, further enhancing comfort at camp. 

We currently have two AIR+FOAM PRO Mattresses on the market, both of which have R-values over 11. Keep in mind what we mentioned earlier: R-values of 6 or higher are suitable for winter camping. Needless to say, these ultra-insulated mattresses are ready for whatever weather you are. 

Our AIR+FOAM PRO Camping Mattress is a self-inflating, rectangular mattress that’s designed to fit in a traditional tent, rooftop tent, RV, van, you name it. It works well in SUVs and hatchbacks, too, courtesy of our included, innovative new Head Support Bridge Attachments, which bridge the gap between your front seats and folded back seats. If you’re looking for versatility, you can’t go wrong with the AIR+FOAM PRO Camping Mattress. 

Our AIR+FOAM PRO Vehicle Mattress utilizes the same incredibly comfortable construction technology, but the mattress shape is curved and contoured to maximize sleeping real estate in the trunk of your SUV or hatchback. If you plan to car camp in ski resort parking lots or at backcountry trailheads this winter, the AIR+FOAM PRO Vehicle Mattress is the way to go. 

Already have a Luno AIR Mattress you know and love? No worries. Grab our Memory Foam Topper to add some welcome warmth to your sleep setup this winter! This topper adds a supportive, insulative layer of foam to help your mattress adapt to cold conditions. Plus, it's super comfy, too.

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R You Going To Winter Camp Or What?

We hope this guide helped you understand R-values and why an insulated mattress is important while camping in cold weather. More importantly, we hope this article inspires you to get out and camp comfortably this winter. After all, winter is one of the best times to camp–there aren’t many crowds, the snowy landscape is nothing short of stunning, and there are powder turns to be had.

Thanks for reading, and as always, we’ll see you on the road–no matter the weather.

–The Luno Crew