| Measures | Pad insulation from the ground |
| Higher | = warmer |
| Summer / 3-season / winter | R1-2 / R3-4 / R5+ |
| Difficulty | Beginner concept |
R-value measures a sleeping pad’s resistance to heat loss — its insulation from the cold ground. Higher R-values mean warmer pads: roughly R1-2 for summer, R3-4 for three-season, and R5+ for winter. Since much body heat is lost downward to the ground, a pad’s R-value matters as much as a sleeping bag’s temperature rating.
Choosing a value
Match it to the coldest ground you’ll sleep on; you can stack pads to add R-values for winter.
Works with the bag
R-value (ground) and the sleeping bag rating (air) together keep you warm on the pad.
Frequently asked questions
What R-value do I need?
As a guide: R1-2 for warm summer nights, R3-4 for general three-season camping, and R5 or higher for winter and sleeping on snow. Cold sleepers and cold ground call for higher values. Modern pads use a standardized (ASTM) R-value, so they can be compared directly.
Can you add R-values?
Yes — stacking two pads roughly adds their R-values, which is a common winter trick (for example a foam pad under an air pad). This lets you boost warmth for cold trips and adds puncture insurance from the foam layer.
R-value vs sleeping bag temperature rating?
They're complementary: the bag's rating addresses heat lost to the air around you, while R-value addresses heat lost downward into the ground. A warm bag on a low-R pad still sleeps cold, so match both to the conditions.
Sources
- Sleep system warmth — The Mountaineers