The Sleeping Mat R-Value Explained

Sleeping outdoors is one of the best things you can do to relieve stress, enhance your mood, and experience a boost of serotonin (the feel-good hormone). That is if you have the right sleeping mat!

The right sleeping pad helps you sleep comfortably without tossing and turning. But how to choose the perfect one? The R-value is one of the first things to consider when deciding on a sleeping mat. If you don't know what the R-value is and its importance, keep reading as we explain it all below.

What is the R-value?

The R-value measures thermal resistance, which is the ability to resist heat loss to the ground. Sleeping pads with high R-values resist heat transfer and keep you insulated from the ground. They help you stay warm and comfortable at night.

R-values usually range between 1 and 7. Some thicker mattresses have R-values in the double digits, but since they are quite thick, they are not very appealing to backpackers (difficult to carry).

How is the R-value measured?

We calculate the R-value of a sleeping mat in a cold chamber. We place the hiking mat between two metal plates and heat the bottom one using an electrical current. One important thing to know is that the plate has a sensor that keeps it at a steady temperature.

We want to measure the ability of the sleeping mat to prevent heat loss from the bottom plate. It will take little electrical current to keep the plate's temperature stable if it is resistant to heat loss. On the other hand, if the hiking mat does not prevent heat loss, it will take a lot of electrical current to maintain the plate at a stable temperature.

Using an equation, the R-value is calculated based on the energy required to maintain the bottom plate's temperature stable. The more current it takes, the lower the R-value and vice versa.

How to pick the best R-value for you

You can select the R-value of your hiking pad depending on the season you wish to use it. Mats with an R-value of 1-2 are usually most comfortable during the summer. They do not retain a lot of heat, which prevents you from overheating in the summer.

R-values of 3-5 work best for 3-season. Purchasing a sleeping mat with those R-values can help you make the most of it because it is comfortable for a wide range of temperatures. Finally, R-values over 5 are best for cold weather.

Dwight's Outdoors Premium Sleeping Mat: Thermarest NeoAir XLite Sleeping Mat

Our NeoAir XLite is the gold standard of mattress. It is lightweight but comfortable and offers one of the best warmth-to-weight ratios of any air sleeping pad. With an R-value of 4.2, it works great in a wide range of temperatures, from warm to cool.

Its WingLock valve allows you to inflate the pad three times faster than other sleeping mats to help install your sleeping setup in no time! It also comes in various sizes, so you can pick the length that best suits your needs.

Head to this page to learn more about this product and get your hands on yours today!

Frequently Asked Questions

What is R-value in a sleeping mat?

R-value measures a sleeping mat's resistance to heat flow — the higher the number, the better it insulates you from the cold ground. It's an industry standard (ASTM F3340) that allows direct comparison between brands and models.

What R-value do I need for NZ camping?

For NZ camping, we recommend a sleeping mat with an R-value of 4.0 or higher. NZ conditions — even in summer at altitude — can be cold overnight, and a higher R-value mat is a worthwhile investment.

Can I combine two mats to increase R-value?

Yes — R-values are additive when stacking mats. A foam mat (R1.5) under an inflatable mat (R3.5) gives approximately R5.0 total. This is a useful approach for winter camping if you don't want to buy a single high-R-value mat.

What is the difference between R-value and temperature rating?

R-value measures insulation from the ground only. A sleeping bag temperature rating reflects the bag's insulation from cold air. Both matter — a warm sleeping bag on an inadequate mat will still leave you cold from below.

Are high R-value mats heavier?

Generally yes — more insulation means more material, which adds weight. However, modern inflatable mat technology has reduced this significantly. The Peak XV Hyperlite 4.9R at 445g is an excellent example of high R-value at low weight for NZ tramping.

Where can I buy high R-value sleeping mats in NZ?

Dwights stocks sleeping mats from Peak XV, Rab, Klymit, and others across a range of R-values. Browse at /collections/sleeping-mats.