The New Sleeping Pad R-Value Standard Has Arrived

New Sleeping Pad R-Value has Arrived

2020 has arrived and the new ASTM FF3340 Sleeping Pad R-Value Standard is being rolled out in fits and starts by manufacturers and retailers. This new standard will make it possible for you to compare sleeping pads across models and manufacturers because it defines a common methodology for measuring the R-value of a sleeping pad.

What are Sleeping Pad R-values?

R-Value measures a sleeping pad’s ability to prevent heat loss (to the ground) when you lie on it at night. Pads with higher R-values do this more effectively than pads with lower R-values. R-value isn’t a measure of warmth per se, but of a pad’s ability to prevent the loss of the warmth that your body generates.

In the past, companies had different ways of measuring the R-values of their sleeping pads or they “estimated” the R-value and didn’t actually measure it. Companies like Big Agnes and NEMO didn’t use R-values at all. Adopting an industry-standard is important so consumers can compare products using the same insulation criteria. The adoption of the sleeping bag temperature rating standard had a similar effect and spurred competition and innovation.

How can you tell the difference between product listings with Old R-values and New R-Values?

  1. The pads with older R-values are almost always on sale.
  2. You can use the table below to determine whether you’re looking at a product listing with an old R-value or one with a new R-value.
Klymit has not published new R-values for their sleeping pads, as of 2-22-20.
Make / ModelOld R Value2020 R-Value
Therm-a-Rest NeoAir XLite3.24.2
Therm-a-Rest NeoAir XLite Women's3.95.4
Therm-a-Rest NeoAir XTherm5.76.9
Therm-a-Rest NeoAir XTherm Max5.76.9
Therm-a-Rest NeoAir UberLite22.3
Therm-a-Rest Basecamp5.86
Therm-a-Rest LuxuryMap6.86
Therm-a-Rest MondoKing 3D11.47
Therm-a-Rest NeoAir Camper Duo2.22.5
Therm-a-Rest NeoAir Venture1.92.2
Therm-a-Rest Original Z LiteNew1.7
Therm-a-Rest ProLite2.42.4
Therm-a-Rest ProLite Apex43.8
Therm-a-Rest ProLite Plus3.43.2
Therm-a-Rest ProLite Plus Women's4.23.9
Therm-a-Rest ProLite Women's32.7
Therm-a-Rest Ridegrest Classic2.62
Therm-a-Rest RidgeRest SOLite2.82.1
Therm-a-Rest NeoAir TopoNew2.3
Therm-a-Rest NeoAir Topo LuxeNew3.7
Therm-a-Rest Trail Lite3.43.2
Therm-a-Rest Trail Lite Women's44.5
Therm-a-Rest Trail Pro44.4
Therm-a-Rest Trail Scout4.83.1
Therm-a-Rest Z Lite Sol2.62
Sea-to-Summit Ether Light XT Insulated Air3.83.2
Sea-to-Summit Ether Light XT Insulated Air Women's4.23.5
Sea-to-Summit Ultralight Insulated Air Women's3.83.5
Sea-to-Summit Ultralight Insulated AirNA3.1
Sea-to-Summit Comfort Light Insulated Women'sNA3.8
Sea-to-Summit Comfort Light Insulated Air4.23.7
REI TrekkerNA5.6
REI Trekker Women'sNA4.2
REI Flash ThermalNew4.7
REI Flash 3-SeasonNew3.2
REI AirRail PlusNA3.3
REI Air Rail Plus Women'sNA3.7
REI Stratus InsulatedNA2.9
REI KingdomNew3.5
REI GroundbreakerNew5
REI KindercamperNew2.5
REI Camp DreamerrNew2.7
NEMO Switchback ULNA2
NEMO Tensor Alpine ULNA4.8
NEMO Tensor UL InsulatedNA3.5
NEMO Tensor UL Non-insulatedNA1.6
NEMO Cosmo 3DNA3.3
NEMO Roamer SINA6
NEMO Nomad CampingNANA
NEMO Vector UL Non-insulatedNA1.6
NEMO Vector UL InsulatedNA3.5
NEMO Astro InsulatedNA2.6
NEMO Astro Non-InsulatedNA1.5
NEMO Astro Lite InsulatedNA2.6
NEMO Astro Lite Non-InsulatedNA1.5
NEMO FlyerNA3.3
Exped FlexMatNew1.5
Exped FlexMat PlusNew2.2
Exped DownMat XP 987.8
Exped DownMat UL Winter77.1
Exped SynMat UL Winter55.2
Exped SynMat HL Duo Winter55
Exped SynMat UL3.32.9
Exped SynMat HL3.32.9
Exped SynMat HL Duo3.32.9
Exped SynMat UL Lite2.52.3
Exped AirMat UL Lite1.71.3
Exped AirMat HL1.91.3
Exped SIM UL 3.83.23.1
Exped DownMat XP 75.95.8
Exped SynMat 965.2
Exped SynMat XP 965.2
Exped SynMat XP 74.94.8
Exped SynMat Duo4.94.8
Exped DownMat Lite 54.13.8
Exped SynMat Lite 52.53.4
Exped AirMat Lite 51.71.3
Exped AirMat Lite Plus 51.71.3
Exped SIM 3.844.6
Exped SIM 54.66.1
Exped SIM Lite 3.83.23.1
Exped SIM Comfort 54.64.3
Exped SIM Comfort Duo 54.64.3
Exped SIM Comfort 7.56.46.4
Exped SIM Comfort Duo 7.56.46.4
Exped SIM Comfort 109.58.1
Exped MegaMat 109.58.1
Exped MegaMat Max 15New10.6
Exped MegaMat Max Duo 15New10.6
Exped MegaMat Duo 109.58.1
Exped DeepSleep Mat 7.5New8.5
Exped DeepSleep Mat Duo 7.5New8.5
Exped MultiMat Uno1.41.4
Big Agnes Insulated Q-Core SLXNA3.2
Big Agnes Insulated Q Core DeluxeNA4.3
Big Agnes Insulated AXL AirNA3
Big Agnes Insulated AXL Trail BossNA4.4
Big Agnes Insulated Air Core UltraNA4.5
Big Agnes Air Core UltraNA1.4
Big Agnes Insulated SLX Tent FloorNA3.2
Big Agnes Third Degree FoamNA1.5
Big Agnes HinmanNA5
Big Agnes Two TrackNA3.3
Klymit Static V1.3NA
Klymit Static V21.3NA
Klymit Insulated Static V4.4NA
Klymit Insulated Static V Lite4.4NA
Klymit Insulated Static V Luxe5NA
Klymit Static V Luxe1.6NA
Klymit Insulated Static V Luxe SLNANA
Klymit Static V Luxe SL1.5NA
Klymit Insulated V Ultralite SL4.4NA
Klymit Double V1.6NA
Klymit Static V LongNANA
Klymit Insulated Hammock VNANA
Klymit Hammock VNANA
Klymit Insulated Double V4.4NA
Klymit Static V Short1.3NA
Klymit V Ultralite SLNANA
Klymit Inertia OzoneNANA
Klymit Inertia X-FrameNANA
Klymit Inertia XLNANA
Klymit Inertia X LiteNANA
Klymit Armoured V1.6NA
Klymit Static V Pink CamoNANA
Mountain Equipment Aerostat Down 7.0NA5

Here’s how to use this table:

  • If you’re looking at the online product listing for the Sea-to-Summit Comfort Light Insulated Sleep Pad at REI which has an R-value of 4.2 listed, you know it’s an old product listing since the current value listed above is 3.7.
  • If you’re looking at an Exped MegaMat 10 listing at EnWild which has an R-value of 9.5 listed, then you also know it’s an older model, since the Exped MegaMat 10 has an R-value of 8.1 when measured against the new R-value Standard
  • You may also find pads listed at retailers that are not on the list above. These may be pads that are no longer produced by the manufacturer but listed by the retailer in order to dump old inventory, again with an antiquated R-value, if any.

Sources: Therm-a-Rest and Exped provided me with updated R-value lists that showed the correspondence between their pads’ old R-values and their new R-values under the new standard. Big Agnes also provided me with the new R-values of their new pads. A big vote of thanks to those companies! I pulled the R-values of NEMO’s new pads from their website and a subset of Sea-to-Summits from the REI website where they are available (the Sea-to-Summit website has not been updated completely yet.)

What about the Sleeping Pad Manufacturer’s Websites?

Therm-a-Rest, NEMO Equipment, and REI are the only companies that have updated their company websites and online stores with the new standardized Sleeping Pad R-values. Exped, Big Agnes, Klymit, and Sea-to-Summit have not fully updated their websites with the new R-values.

All of Therm-a-Rest older pads have been renamed such-and-such “Classic”, in part to indicate that they have the old stick valve and not the new WingLock version. That naming scheme hasn’t been adopted by other retailers yet, so if you desire clarity and a discount on the old classic pads, shop at the Therm-a-Rest website. The only difference between the Classic pads and new pads is the valve and the way that the R-value was measured, not the amount of insulation in the pad. I know that’s confusing. The measurement methodology is all that’s changed, not the pads themselves (with the exception of the valves). I don’t know if that’s true of other brands though.

Why is the New R-Value Standard Rollout such a Cluster…?

The new rollout is messy and confusing because retailers are trying to sell off their old-pre-standardized sleeping pad inventory alongside the new standardized models without changing the product names or differentiating between pre-standardized R-values and ones that conform to the new standard. Is it really too much to ask retailers to fix this? I wouldn’t hold your breath waiting. Although, it seems that it would be in the manufacturers’ best interests to help retailers list the right information.

Make this one simple change to sleeping pad product listings.

Here is the ONE simple change that retailers and manufacturers could implement on their websites tomorrow if they wanted to provide you with up to date R-values using the new ASTM FF33400-18 R-value Standard:

  • Add a new attribute to every sleeping pad listing called: “ASTM R-Value” and include the new R-value for pre-existing or new pads if one exists. If not, fill the field with “Not available.” You don’t even have to get rid of the old R-value if one is present.

Why Not Slap a Sticker on Old Products?

Why didn’t manufacturers or retailers just slap a sticker on existing inventory boxes to indicate an R-value change if the underlying product didn’t change? Your guess is as good as mine. Discounting existing products just because you need to change the R-value on the packaging (or the online product listing) is stupid.

Do you think that consumers deserve accurate online retail product listings?

I do. This is crazy.

Editor's note: Help support this site by making your next gear purchase through one of the links above. Click a link, buy what you need, and the seller will contribute a portion of the purchase price to support SectionHiker's unsponsored gear reviews, articles, and hiking guides.

Most Popular Searches

  • exped rvalue
  • new r value
  • r value 2020

65 comments

  1. Great comparison update! Thanks!

  2. Philip,
    Thank you for all the hard work on this. Many people benefit from your labors. I think it will all sort out during this year. 2021 will have lots more clarity… except for whatever other issues we’ll all be dealing with then!

  3. This is really great to finally see coming to fruition!

    Interesting to see the new vs old ratings: for example, I see that the Therm-a-Rest Original Z Lite and Z Lit Sol are both rated 2 … does this mean that their claim that the metalized coating increases warmth by 20% is bogus?

    • Slowly getting there. I’ve been a big proponent of Pad R-values for years and I’m just trying to help the process along on the consumer side.

      Metalized coating: Interesting observation. I’ll have to look into that one. Thermarest is always very forthcoming with me.

      One of my takeaways from this list is that people should buy women’s pads to get the most insulation for $$ and weight. Brands would probably be better just getting rid of their men’s models altogether. Less wasteful too.

      • How can the women’s Therm-a-Rest NeoAir XLite be the same size and weight yet have a higher rating, 5.4 vs men’s 4.2 ?

      • They’re usually not the same size (usually shorter length) and they make women’s pads more insulating because they are smaller than men and don’t generate as much body heat.

      • I bought the Thermarest Women’s Prolite 4 self inflating pad a number of years ago because it was cheaper, lighter, and had better insulating properties. It’s still being used as a car camping pad. The NeoAir XLite Women’s is lighter, cheaper and warmer than the men’s pad (although a bit smaller, but at 5′-8″ height, that wasn’t an issue for me).

        The women’s sleeping pads are definitely a good choice for many.

    • Thoughts on the metallic coating:

      It could also be that the new R-value test doesn’t measure reflected radiant heat because a heated manikin is not used in the test to simulate a person. Quoting from the ASTM standard “This test method covers the measurement of the thermal resistance of camping mattresses in conditions of steady-state heat transfer, using a two-plate apparatus. The camping mattress is held under constant compressive force between a guarded hot plate and a cold plate. The primary heat transfer for this method is one dimensional, vertically through the camping mattress thickness.” I could see how a reflective coating would not register under those circumstances, while it still might work if you were lying on top of it. I’m just suggesting an alternative explanation.

      • They must be accounting for radiant heat reflection since that is what the Thermarest Xtherms depend on and they have actually gone up in rating.

      • Interesting thought, and it makes some sense to me … I’m curious to hear what Thermarest and/or MEC & REI have to say about it. Of course, the “total” insulation/heat value is probably going to be most meaningful to consumers …

      • From Wikipedia

        “To perform properly, radiant barriers need to face open space (e.g., air or vacuum) through which there would otherwise be radiation.” followed by an FTC footnote.

        “According to the US Department of Energy, “Reflective insulation and radiant barrier products must have an air space adjacent to the reflective material to be effective.”” Also footnoted.

        The XTherm has air space between the surface of the pad and the internal reflective material, but the Sol places the reflective material directly on the surface that is laid upon with basically no air space. Placing a Sol under an air pad should work pretty well though.

        I think the cold plate is going to pick up any kind of heat coming into contact with it, radiant, conductive, or convective.

    • Hey manufacturers, whatcha thinkin (other than money)???
      We now have to compare the old vs new r-values and then extrapolate from r- value to Min./ Comfort temperatures and acceptable weight and then apply that to our particular hiking excursion… simple.
      I’m moving to Germany.

  4. It would be great if the US would adopt the SI R-value rather than the Imperial R-value. This causes a huge amount of confusion for purchasers of US brand mats in the rest of the world who think they’re buying something far warmer than it actually is.

    1 R-value (US) = 0.17622 R-value (SI)

    • Not warmth, but insulation.

    • What version of R-value does Exped use? I’ve always thought it was the US version despite the fact that they are a Swiss company.
      BTW, I check the text of the actual standard and see no mention of which R-value is used. I assume it is the US version though.

      • I believe Exped used the Swiss Federal Material Labs (EMPA) protocol for there R value ratings prior to adopting the new 2020 ASTM protocols.

  5. Could you please add Paria Outdoors Pads to this list?

    • No. Last I checked Paria doesn’t test the R-vale of their pads but is one of those manufacturers that uses “estimates” which is exactly the kind of thing that the standards process is designed to fix. If they start testing the insulation values of their pads rather than pulling numbers out of the air, I’d add them. I reviewed one of their pads last year and that’s when I discovered they don’t send them out for R-value testing.

      • What is hard to understand is the variations in R values across pads made by the same manufacturer. For example, some of Thermarest pads have gone up in R value while others have gone down. Did they use different tests for different models? Same issue with Exped. The change I ratings seem primarily linked to the testing methodology rather than changes to product design. Comparison becomes more difficult when manufacturers start changing their pads.

      • Same test all models.

  6. Anyone know if the new standard considers the pumping action caused by breathing or other movements?

    For example an air pad will lose heat faster at the edges with such forced air flow

    • It doesn’t – I bought the text of the standard to read. I’ll requote from my comment above.

      “This test method covers the measurement of the thermal resistance of camping mattresses in conditions of steady-state heat transfer, using a two-plate apparatus. The camping mattress is held under constant compressive force between a guarded hot plate and a cold plate. The primary heat transfer for this method is one dimensional, vertically through the camping mattress thickness.”

  7. Awesome list. Learn something new everyday.

  8. Thx!!!
    I saw the updated neoair r values a couple weeks ago and was considering getting the new higher r value version.

  9. Thanks for the post Philip! Really appreciate all your work on this.

    Based on the new standard, what would you say is the minimum R-value for summer, 3-season and winter pads?

    If this is more complicated to answer than I think, feel free to say so.

    Regardless, good to see more standardization in the industry.

    • R=2 for summer, R=3 for autumn and spring or if you sleep cold in summer, R=5 or higher for winter
      Women and small men generally need an additional R=1 for all seasons because they are shorter, smaller, and generate less heat.

  10. Any update on Klymit pads? I see they list their R-values on the site, but not sure if they’re up to standard. They never seem as insulating for the weight as other pads probably because of the welded “v” seams (where most of the heat is probably lost). Had to buy a yoga mat last winter mid-trip to use on top of the Insulated Static V as I was freezing my butt off otherwise.

  11. Definitely a good thing. Thanks for the article.

    Your links to REI for the Z-Lite models still list the old values of 2.2 and 2.6 rather than your updated values of 2. Same for the Ridgerest/sol. Thermarest do not seem to have updated their site for these pads either. I didn’t check other listings. Just wondering where you got the updated numbers you quote.

    • All of my Zlite and Ridgerest links go back to Therm-a-rest website and always have. I got the updated R-values right from the Thermarest website on the product pages next to the ASTM logo on each product’s description tabs. My table has two columns with R-values. The pre-2020 R-values that were published before the new standard came out and the ASTM-FF33418 R-values that are current based on the new standard. I happen t have a list of all the pre-2020 R-values for most vendors and took the old R-values (pre-2020) from it

      But you’re right, it doesn’t look like thermarest has updated the old specs deeper in their website on the spec tabs of their products. I’ve alerted the head of marketing at Cascade Designs to that issue, so he can get it fixed as soon as possible.

  12. No wonder the Woman’s XLite was way to hot for me at the new standardized rating of 5.4 R. The radiant barrier works for sure, but it just made me hot and clammy over 45° – 50°.

    I’m a three season, 3.0 R, all night long.

  13. Thank you for this info. It is helpful. I have a Therm-A-Rest NeoAir XLite that I see has gone up in R Value. I hope other manufacturers will get on board. I want to know what my Klymit Static V Insulated pad is. I’ve always thought it’s about a 5. That, coupled with a Ridge Rest, should get me to a 7…right?

    • I hope Klymit gets on board. I’d imagine that it will be very difficult to compete if they don’t.
      I believe they rated that pad a R=4.4 in the past, but it’s hard to say what it will be with the new R-value standard.

      • Just in. It’s 1.9 it seems

      • I have a hard time believing the ratings on Klymit pads. They really took a hit with this. I have used an insulated light Klymit pad up here in Canadian winters, and compared it to both exped and thermarest. Of course exped was warmer, but it compared favorably to an insulated thermarest supposed to have an above 4 r value. So those new values don’t make much sense to me as a Klymit lover.

      • Klymit did publish them so I suspect they believe them. What it says to me is that the air channels in klymit pads don’t work.

  14. Thanks for this heads up. Very informative and an industry STANDARD at last!
    I wish you could have included the 2 REI FLASH mattresses update R values but I bet REI will soon publish them.

    • I called REI customer service regarding the new mattress R value standards. They advised me that in 2019 they began using these standards and that my two REI FLASH mattresses (3 season and All Weather) were rated using the new system.

  15. I subscribe to several outdoor/hiking sites and always look forward to this site. Simply the most informative…thanks for the new information.

  16. Phillip
    Awesome work and a great benefit to the backpacking community.

    To the question:”Why didn’t manufacturers or retailers just slap a sticker on existing inventory boxes to indicate an R-value change ..”
    I have not worked in retail but I have worked with technology products that went through two tiered distribution. At any one point in time, a large portion of your product is flowing through the channels. It is impossible to get channel partners to apply labels. It is very expensive to run product through a production line to apply labels after the fact.

    The last thing the vendor or the customer wants is a mix of old stuff with labels and old stuff without labels flowing through the distribution chains and available at the end point of sale. It is therefore cleaner just to cut over to the new revision at the factory. No labels.

  17. Hi. This is great – thanks for posting! Do you happen to have a chart of the weights of these pads anywhere? Combined with the R values, that would be extremely useful.

  18. Thanks for all your work on this, now and over the years. So helpful!

    I’ve been on a quest to find my ideal pad. I’m a cold sleeper who likes his comfort, but also wants to keep weight down. Based on your recommendation, I’m going to try the S-to-S Ether Light XT this season. I noticed its rating went down, which doesn’t seem to be uncommon, and as I recall you predicted that in your review.

    The observation about women’s pads is interesting. I’m too big for most (all?) women’s pads, but I’m certainly going to encourage my daughters to look at that.

  19. Klymit has published the new R-Values on its website, and they go down drastically…

  20. Those new numbers are good for the neoairs users, dissapointed that the sea-to-summit pads appear to be not as warm.

  21. It looks to me like Klymit is reporting the old and the new values on their web site. (Those lower values aren’t the European values, are they? I have not taken the time to check that.) But I don’t doubt that there could be a great reduction based on the way the tests are conducted. I’ve used a Klymit insulated pad (R=5.0) with a 20F down sleeping bag and been toasty warm in the low 20sF. But when I used the same pad with a 20F quilt in similar temps, I was quite cold. I wonder if those uninsulated gaps (the air channels?) require the use of a bag to fill them in, and a quilt just doesn’t do that.

    • Those lower values are the ASTM3340-18 R-values.

      • Odd that they are reporting the old and new values. I have not found an explanation on their web site.

      • Why were the klymit numbers removed? I checked the website for the insulated static v and it is still stating an r value of 4.4.

      • Klymit contacted me and told me that they made a mistake and accidentally posted incorrect “new” R-values on their website. A major PR blunder….

        The ones that are there now are the old non-standardized values and it’s really anybody’s guess how valid they are. In the future, if the R-value is not labeled ASTM 3340, you should assume it was “conceived” before the new industry standard went into effect.

        Here’s a portion of the email that Klymnit sent me.

        Hi Philip,

        Klymit had a soft launch of our new website at the beginning of this week and unfortunately all of our data did not load over correctly. As a result, the ASTM R-values for all of our insulated sleeping pads are incorrect. Our insulated sleeping pads have yet to be tested for the new ASTM R-value standard. I noticed you posted the specs on your website, so I wanted to point out our error to you ASAP. We’ve since corrected the error on our end.

        The introduction of the ASTM R-Value standard will be a rolling change for us throughout the new year as we test the sleeping pads and update our packaging and website specifications.

  22. Hi Philip, thanks for your invaluable work. Please help me: why with the new standard all thermarest top pads such as neolite serie xlite/xtherm etc value a have allincreased but correspondent sts ether serie decreased? I want to buy an Ether light xt insulated following your great review and I am puzzled by these data.Thank you. Sorry for my poor english.

    • I mean, now xtherm new increased R-value compared to Ether light xt insulated decreased value is 6.9 vs 3.2 that’s more than double! Since the latter is your new “favorite” pad would you say difference is really that huge and apparent in the real world? Thanks again

    • There was no standard before. Now they are measured the same way, so nothing has actually changed except that you can compare them. You couldn’t before because they were measured differently.

    • Because R value does not mean comfort. The ether light is 4 inches thick and super comfortable. The xtherm is 2.5 inches thick and feels like wood.

      • I’m sold, I’m buying one!
        I’m big and warm sleeper guy so in case of extreme cold my zlite underneath will fill the gap and do the trick. I don’t see any reason to go with the xtherm now. Actually “made in US” was still a nice appeal compared to the other Asia made brands. In this respect do you feel STS production quality is inferior by any means ?

      • Therm-a-Rest pads are only assembled in the USA. The components all come from Asia. STS quality is just fine. Nothing is actually made in the US anymore except….

  23. You are right, and the same goes for much hyped and priced USA made HMG, SO backpacks and so on I guess.
    Except…? Now I’m interested :)

    • HMG packs are definitely hyped. If you’re in Europe or the UK, I’d recommend Atom Packs.

      • Yes EU, I am from Italy. Your input comes in at the right time, I need to find a quality lightweight pack. Actually I was about to pull the trigger on a discounted black 4400 windrider Tall for 320€ (RRP is 390€). Which Atom pack is comparable in capacity and “heavy” loads comfort? I’m kind of big and not a pure 10 lbs-obsessed ultralighter, for longer or winter trips I can hike with 40 lbs as well. Actually I am ok with a 50-70 lt range compressible but as I said the 4400 has good price so no much choice in the HMG department. I’ve been looking at SO Divide/Unaweep (whopping 500€ all included from the single EU retailer) too. What would you suggest? I value quality, made in USA /EU and luckily not tight on a budget. Thank you

      • Not familiar with their bigger packs. Go to their website and you’ll be able to figure it out pretty quickly.

  24. Ok thank you.

Leave a Reply

Your email address will not be published. Required fields are marked *