The R-value of a sleeping pad shows best how well it insulates. Simply said, it measures the resistance against heat loss. That resistance decides how well materials in pads preserve the heat of the body when you lie on them overnight.
At backpacking or camping the R-value of a sleeping pad points to how well it stops heat loss when you sleep on it. Pads with high R-value do that more effectively than those with low.
What R-Value Means for Sleeping Pads
High R-values mean more warmth. It is a standard measure that each producer must use for claims, so it matters to look at this number carefully during buying of a new sleeping pad. Before makers used their own ways for counting it, what blocked objective comparison.
For choosing the right R-value, think about the seasons of your camping. Some pad with 1 to 2 answers for basic needs. If it goes above 2.5, you consider it medium to high, so it serves for three seasons: summer, spring and autumn.
In cold weather you need a sleeping pad with at least 5. The need for heat changes between men and women, and also between small and big people.
Women require higher R-value because they have less body mass than men. Adding 1 to the R-value usually helps women and other cold sleepers. If a model comes in different sizes, all of them have the same R-value, unless you say otherwise.
R-value is additive. Stacking two sleeping pads, you add their R-values. Combining a closed-cell foam pad with an uninsulated Klymit Static V, you get about 4 of R-value for less than 100 dollars and about 2 pounds.
Always bring a foam pad in winter, because it insulates during cooking and melting of snow.
Match with a sleeping bag matters also. A pad that answers to the bag maximizes comfort and warmth. According to EN 13537, the labeled temperature of a bag measures with high R-value pad.
For reaching that heat, your pad must have equal R-value.
Inflatable pads commonly insulate less than promised, while foam more exactly reach their value. The ground also affects. Sleep on thick forest leaves, heated by the sun all day, is a lot different experience than on hard, wet dirt after rain, even if the pad same.
Comparing pads according to weight, thickness, materials, length, width and R-valuecan seem like too much, but R-value stays the key for heat.
