Sleeping pad R-value calculator
- Target: a pad (or stack of pads) totalling R 2.5 on the ASTM F3340 scale
- R-values add: a closed-cell foam pad (about R 2) under an inflatable raises the total by that much
Matches for this answer
LLUAII Self Inflating Sleeping Pad with Electric PumpUnder $100Check price
TaskStar 4" Self Inflating Sleeping Pad for Camping with PillowUnder $50Check price
Hikenture 4" Thick Self Inflating Sleeping PadUnder $100Check price
Hikenture 4" Thick Self Inflating Sleeping Pad with Electric PumpUnder $250Check price
Car camping pads and cots
Every budget band below comes from the Amazon listing price when this page was built; the link shows the current price.
- TaskStar 4" Self Inflating Sleeping Pad for Camping with PillowUnder $50Check priceSpec sheet
Heavy Duty Camping Cot for AdultsUnder $100Check priceSpec sheet
Suteck Camping CotUnder $100Check price
HABUTWAY Camping Cot with MattressUnder $250Check priceSpec sheet
REDCAMP 2 Person Folding Camping Cot for AdultsUnder $250Check price
Teton Outfitter Camping CotUnder $250Check priceSpec sheet
Exped MegaMat Ultra Sleeping PadUnder $500Check price
Exped MegaMat Sleeping PadUnder $500Check price
How does this calculator work?
R-value measures resistance to heat flow through the pad. Since 2020 most major brands test to the ASTM F3340 standard, so an R 4 from one brand is comparable to an R 4 from another, which was not true before.
The ground pulls heat out of you far faster than air does, and your sleeping bag insulation is crushed flat underneath you, so the pad does nearly all the work below you. The bands here follow the common guidance: under R 2 for summer, R 2 to 4 for three seasons, R 4 to 5.5 around freezing and above R 5.5 for winter.
A cot adds about R 1 to the requirement because air moves freely beneath it. Cold sleepers add another 1. Warm sleepers can take half a point off.
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Frequently asked questions
What R-value do I need for 30 degree camping?
About R 4 on the ground, and closer to R 5 if you sleep cold or lie on a cot, where moving air cools you from below. R-values add, so a closed-cell foam pad under an inflatable pad raises the total.
What R-value do I need for car camping?
For most spring to fall car camping with overnight lows in the 40s, an R-value of about 3 is enough. If you camp into the shoulder seasons or at elevation where lows hit freezing, aim for R 4 to 5. Car campers can carry thick pads, so there is little reason to buy below R 3 unless you only camp in summer heat.
Is an air mattress warm enough for camping?
A standard queen air mattress is comfortable but insulates poorly, roughly R 1 or less, because the large air chamber circulates and cools. Below about 50F it feels cold from underneath. Laying a foam pad, a self-inflating pad or a thick wool blanket on top of the mattress, under your bag, fixes most of it.
Can I stack two sleeping pads?
Yes, and R-values add. A closed-cell foam pad around R 2 under a self-inflating R 3 pad gives roughly R 5. Put the foam pad on the bottom so it protects the inflatable from punctures. Stacking is a cheap way to extend a summer pad into cold nights without buying a new one.
Sources
- Sleeping pad R-value testing: ASTM F3340, the standard test method most major pad makers now use, so ratings are comparable across brands.
- R-value by overnight low: manufacturer guidance and common outdoor-retailer temperature charts, labelled CONVENTION in the calculator.
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After the list, a few short emails, then a couple a month at most. Unsubscribe anytime. You can also read every setup free on this site.Researched guidance, not professional advice. Figures are published specifications or clearly labelled conventions; check your own gear's manual and your campground's rules.
