You’ve just woken up from a bitterly cold and uncomfortable night’s sleep. It felt like every stone and stick had been strategically placed to jab you in the ribs just as you were finally managing to drift off. That darn sleeping bag didn’t seem to make a shred of difference in keeping you warm. And now you need to roll up that bulky foam pad and strap it back onto your pack. Welcome to the world of sleeping mats. What you’d think should be a rudimentary outdoor purchasing decision—buy something soft and spongy—turns out to be anything but.
If there’s one thing you need when spending multiple days outdoors, it’s a good night’s sleep. A high-quality sleeping bag is an essential first piece of your overnight outdoor kit. A close second is the right sleeping mat. You can still go cheap and have a good night’s sleep (we explain how later), however this guide will ensure you select the right mat for your conditions.
There are four essential criteria you should consider when buying a new mat. Price, Weight, Comfort and Warmth. Three of these four are straightforward to explain and understand.
Price is the easiest to cover first, as it will generally be a reflection of the other three criteria. If you want something super light, super comfy and super insulating, you’re gonna have to pay for it. That said, if you’re happy to make sacrifices and forego some of these, then you’ll likely help your hip pocket. And as we’ll explain, in some circumstances, you can go cheap without giving up too much comfort.
Expect to pay anything from $50 for a no-name sheet of foam up to $1000 for a top-of-the-line sleeping mat from one of the major outdoor brands.
The biggest factor adding to a sleeping mat’s weight is simply the amount of material used in the construction. The bigger the mat, the more materials are used and the heavier it will be. Of course, there are ultra-light materials out there (especially in fabrics) that will reduce the weight, but we’re talking grams of weight savings rather than the savings of taking 30cm off the size. Insulation will also add weight. The better the insulation, the more of it will be used—back to the material argument—and the heavier it will be.
If weight is your primary consideration, go for something small and with minimal insulation. And while this approach might work for an ultra-light hiker where weight saving is everything, remember that saving those few extra grams for a multi-day hike might not provide the most comfortable sleep either. It’s also worth remembering that those ultra-light fabrics are also less puncture resistant to heavier more durable materials.
When it comes to comfort, generally the fatter the mat the more comfortable it will be. There is simply more padding between you and whatever is on the ground. However, just as we all have different preferences for the type of bed mattress we sleep on, similar considerations apply with sleeping mats. The surface of the mat (smooth versus textured), baffles or pockets in the mat versus a more uniform flat surface, and obviously length and width will all play a part in how comfortable you find a sleeping mat to be. Comfort is probably the one ingredient that is most difficult to standardise, as comfort will largely differ depending on you and your specific sleeping requirements. Best bet is to try out a few different mats on the floor of your local outdoor retailer.
Warmth is a little misleading to describe sleeping mats, as unlike a sleeping bag—which is actually designed to keep you warm—a sleeping mat is really designed to prevent you getting cold. The ground conducts heat up to 60 times faster than air, and if sleeping on snow or ice can even be 90 times more conductive. This means a huge amount of heat can be lost to the ground. A sleeping mat helps negate this heat transfer. This resistance to heat transfer is indicated by an R-Value.
Scientifically, an R-value is a measure of resistance to heat flow through a given thickness of material. It’s calculated by measuring the temperature difference between two surfaces and heat flux (or the amount of heat transferred per unit area per unit of time). Sounds complicated, but effectively what this means is that the higher the R-value, the greater the resistance, and hence the better thermal insulating properties of the object. This measure isn’t confined to the outdoor industry. R-value is commonly used in the construction industry to rate the thermal resistance of building materials (insulation, windows, fiberglass etc).
R-value is correlated to the thickness of the material. Although different materials of the same thickness may have different R-values, the same material at different thicknesses will have different R-values. In short, the thicker (and generally heavier) the material is, the higher the R-value will be. R-value is also both cumulative and linear. This means that layered materials will provide a higher R-value. For example, if you have a R-Value 2 rated sleeping mat on top of a R-Value 2 rated foam mat, you’ll end up with an R-Value of around 4, which will be twice as effective as just one mat.
And this is where our “cheap” sleeping mat tip comes into a play. You might use a low cost, foam mat for use when the weather/ground is warm. These are super cheap and can be thrashed about without too much concern. The ground might be as warm or warmer than the ambient air temperature, which means there will be minimal heat transfer loss and the mat is really just to provide some cushioning on the ground. For colder temperatures you can then supplement your foam mat with a more expensive mat that can sit on top of your foamy. You might get away with not having to purchase a really expensive mat at all, but still have just as comfortable and insulating sleep with you two-combination cheaper mats. This configuration was popularised by the mountaineering community. In addition, with this configuration you might also be able to get away with a cheaper (or lighter) sleeping bag, especially in warmer conditions.
The R-value of sleeping mats will generally range between 1 right up to 9+, although these very high rated mats are typically too heavy and bulky to be carried and are generally only used for car camping. The general consensus is that a mat rated between 0 and 2 is good for summer conditions, between 2 and 3 for spring/autumn conditions, 3 to 5 for winter conditions, and 5+ for extreme cold conditions. (Remember, a high R-value won’t make you hot, it will just provide better insulation against the cold ground).
R Value and ASTM Testing
Until very recently, there was no industry standard in how R-Value was actually measured. This meant manufacturers could really determine and publish their own value. This changed in early 2020 with a new industry standard, the catchily-named ASTM F3340-18. ASTM F3340-18 provides a standardised testing protocol for testing and measuring sleeping mats. As outdoor brands start adopting this new standard, comparing mats across different brands will become easier. You may even find that some mats already on the market end up with a different R-Value. This doesn’t mean they have suddenly become warmer or colder, but rather the new testing methodology has adjusted the value. The ASTM standard isn’t a legal requirement, so not all brands will use this new standard. However only brands that do adhere to the new standard can use the ASTM markings.
Should I just buy a mat with the highest R-value?
The short answer is yes. And no. Or maybe. Since a high R-value alone in a mat won’t make you even a jot warmer on the hottest of summer nights, a mat with a high R-value will provide more versatility as to when it can be used.
The no answer, however, isn’t merely that high R-value mats may be more expensive and bulkier and heavier than low R-value mats; it’s that the bit about high R-value mats not warming you up comes with a caveat. While it’s true that high R-values alone won’t make you hotter, many mats incorporate insulating materials to slow the loss of heat retained within the mat. This means a higher R-value mat may not allow you to cool down as efficiently as a mat with a lower R-value. This could be a problem in very warm temperatures where you want the ground to cool you down through heat loss.
Types of Mats
Air Pads or Inflatable Mats
These are the most popular mats on the market and include all those mats which you blow up (or use a pump). Most new mats on the market are now inflatable, with weight, size and thickness being the biggest advantages. However, filling a thin laminated fabric with air and then laying your 50-100kg body on top of it can and does cause air leaks. Being several days away from civilisation with a leaky mat can be pretty miserable. Always carry a patch kit with you just in case.
The advantages of an inflatable mat include that they:
- Are thickest (and most comfortable)
- Often incorporate extra layers between the layers for improved insulation
- Allow easily adjustment of the mat’s firmness
- Are generally light and compact
On the downside, inflatable mats are:
- Easier to puncture
- Not always good for side sleepers
- Sometimes made of loud, crinkly material
Self-inflating mats are constructed using a type of foam designed to automatically expand once opened up. Self-inflating is a bit of a misnomer, as even these mats will likely require a couple of breaths at the end to get to the desired firmness. Nevertheless, most of the inflation is automatic.
The advantages of self-inflating mats are that they:
- Are often quite soft
- Tend be provide better (higher) insulation
- Are better for side sleepers
- Are often cheaper than inflatable mats
Disadvantages include that they are:
- Often heavier and bulkier than air mattresses
- Can get holes
Closed Cell Foam Pads
Foam mats have several big advantages. They are virtually indestructible. You can rip, tear, slash, crush, smash and bash a foam mat and it’s likely still useable. They can’t puncture. They’re light. And they are cheap.
But they are also come with some big disadvantages. They’re bulky and they’re generally the least comfortable. They are often very thin, and you may feel every stone or pea underneath you.
Nevertheless, because of their light weight, their durability and their insulating benefit, they’re often great as the base layer for your sleep system. And if you bivouac, better to trash your cheap foam mat on rocky ground, rather than your thousand-dollar Gucci mat.
Mats will come in varied lengths and widths. A ‘Long’ mat is anything around 198cm (78 inches). ‘Regular’ is anything around 182cm (72 inches) and ‘Short’ (or ¾) is anything 120cm (47-48 inches).
The standard width of a mat is around 50cm wide (20 inches), whereas wide mats can be 63-75cm wide (25-30 inches) .
A tapered ‘mummy’ shape will shave off weight for a minimalist trip, whereas a rectangular shape will provide the greatest surface area.
Not only do women tend to sleep colder than men, but their body shapes and habits are also different. Women’s specific sleeping mats tend to be narrower in the shoulder and wider from hip to knee to accommodate not only a typical woman’s body shape but also women’s tendency to sleep on their sides.
Storage and in the field
The best way to store a mat is unrolled with its valves open. This will allow moisture to escape, and for the insulation or foam to expand to its natural thickness. Storing mats for a short period in a compressed state won’t damage them, but it will take longer for the insulation or foam to expand. Before heading out, fully inflate your mat and leave it out for a couple of days.
When out in the field, remember that during the day, the air in your mat might expand. It’s a good idea to open up the values in warmer weather. Your mat isn’t going to pop, but a fully expanded mat will place added stress on the internal baffles and seams.
Brands we Recommend
Now that you have all the information you require to help you select the right mat, which brands should you consider? There are literally hundreds, if not thousands of mats available online. Search ebay and over 8000 listings come up. However, we recommend the following brands because they have a long-established history of developing sleeping mats specifically for outdoor use. This means the materials, construction and technology used will all be superior to a cheap no-name product. The exception is perhaps foam mats, but even then, there can be huge quality differences. If you want something you can rely on for years to come, then (as always) it’s worth making the investment in a quality product.
Sea to Summit
Australian owned and designed, Sea to Summit have developed several innovations across their range. In particular, STS has focused on incorporating their mats into entire sleep systems, thinking about how sleeping mats integrate with sleeping bags, pillows and liners.
Swiss company Exped were the first company to introduce down-filled sleeping mats. This insulation can allow mats to have extremely high R-Values for their size and weight.
Although US-based Therm-a-Rest made their name from pioneering self-inflating sleeping mats—they produced the first ever self-inflating mat in 1972—they now produce a significant range of air-filled mats.
US company Nemo Equipment is a relative newcomer to the Australian market, but nonetheless has a quality range of mats to suit most needs.
Klymit have taken ultra-light to a new level. Only producing air-filled mats, not all their models are for everyone (for some lines, think Swiss cheese sleeping mats with loads of holes). If you’re wanting a crazy light mat, though, they’re hard to beat.