Sleeping Pad R-Value Guide (2026)

A cold night in a good sleeping bag usually starts at the ground. Your weight crushes the insulation under you, so the pad does most of the work between you and snow or frozen soil. The R-value on the pad tells you how well it does that job, and since 2019 the number means the same thing across brands.

How we chose: we did not test these pads; we compared R-values the makers publish under the ASTM F3340 standard, weights and dimensions, and kept only pads sold by Amazon.com or the brand's own store and in stock on September 29, 2026.

Six pads by R-value

Prices are Amazon's, as of the time shown, and subject to change. Details

Therm-a-Rest's product pages, such as the XTherm NXT and Z Lite Sol, point to ASTM F3340-18 as the standard behind their R-values, and NEMO publishes R-values under the same standard, as on its Tensor All-Season page.

What an ASTM R-value measures

R-value is thermal resistance: how well the pad slows heat flowing from your body into the ground. Higher is warmer.

NEMO, which helped develop the standard, says ASTM F3340 was ratified in fall 2019. The pad sits between a warm plate and a cold plate, and "the test works by measuring how much energy it takes to keep the hot plate at body temperature." The more energy it takes, the lower the R-value.

Therm-a-Rest's explainer says the standard was finalized and published in 2019 and that its older ratings came from "a different procedure." When you shop, a pre-2020 R-value, or one with no mention of ASTM, is the maker's own number and may not compare with the pads above.

How much R-value you need

REI's sleeping pad guide puts pads for extremely cold weather at R 5.5 or higher. NEMO's advice is simply that the colder it is, the higher the R-value you want.

Here is how we would use that:

• Summer, warm ground: R 1 to 3. A foam pad or a thin air pad.
• Spring and fall, nights near freezing: R 3 to 5. The XLite NXT's 4.5 sits here.
• Winter, snow or frozen ground: R 5.5 and up. The XTherm NXT (7.3), the Tensor Extreme (8.5), or a stacked pair.

If you sleep cold, add a margin. A pad cannot make a thin sleeping bag warm, and a warm bag on a thin pad will still leave your back cold, because the bag's insulation is crushed flat where you lie on it. See our sleeping bag temperature ratings guide for the other half of the system.

Stacking pads: R-values add

NEMO says plainly that "R-Value is additive, which means that you can use two pads and add their R-Values together." REI recommends the same winter setup: a closed-cell foam pad under a high-R air or self-inflating pad.

So a Z Lite Sol (R 2.0) under an XLite NXT (R 4.5) gives about R 6.5, warmer than either pad alone and past REI's 5.5 line. Under an XTherm NXT it gives about R 9.3.

Stacking does three more things. The foam protects the air pad from punctures on crusty snow or rocky ground. REI notes it also forms a barrier against moisture that collects under a pad on cold ground. And if the air pad fails at 2 a.m., you still have R 2.0 under you instead of nothing.

Pro tip: put the foam pad on the bottom and the air pad on top. The foam takes the snow, rocks and ice; the air pad stays clear of anything sharp.

Which pad to buy

• Winter backpacking, one pad: the NeoAir XTherm NXT, R 7.3 at 15.5 oz.
• Already own a three-season pad: add a Z Lite Sol underneath.
• Three seasons now, winter later: the NeoAir XLite NXT, R 4.5 at 13 oz, plus foam when it snows.
• Tall or broad: the NEMO Tensor All-Season Long Wide, R 5.4.
• Coldest nights, no stacking: the NEMO Tensor Extreme, R 8.5.
• Car camping: the BaseCamp, R 6, too heavy to carry far.

Cold-weather care for air pads

The XTherm NXT, XLite NXT and BaseCamp all come with a pump sack, per their listings. Use it instead of your breath on a cold night; it is also faster when your hands are cold.

Self-inflating foam pads like the BaseCamp inflate slowly in the cold. Therm-a-Rest's listing says to inflate it and leave it fully inflated for 2 to 4 hours before the first use, which is easier at home than at a cold trailhead.

Staying warm through the night

A good pad and bag only work if you go to bed warm and dry. Change out of damp layers, eat something, and keep a hat on. If you wake up cold, add a layer before you lie there shivering.

The CDC's hypothermia guidance lists shivering, exhaustion, confusion, fumbling hands, slurred speech and drowsiness as warning signs, and calls a body temperature below 95°F a medical emergency. Someone who cannot warm up in their bag needs dry clothing, shared warmth and help. This page is not medical advice.

Related: how to layer for a cold hike and down vs synthetic insulated jackets.

Frequently Asked Questions

Is an R-value of 4.5 enough for winter?

On its own, not by REI's measure: REI puts extremely cold weather at R 5.5 and up. Stack an R 2.0 foam pad under it and you are at about R 6.5.

Do old R-values compare with ASTM R-values?

Not reliably. Therm-a-Rest says its pre-standard ratings came from a different test procedure, so compare ASTM figures with ASTM figures.

Does a wider pad keep me warmer?

It keeps your elbows and knees on the pad instead of the cold tent floor. The R-value is the same across sizes: Therm-a-Rest lists 4.5 for every XLite NXT size and 7.3 for every XTherm NXT size.

Can I use a closed-cell foam pad alone in winter?

Only with a lot of foam. The Z Lite Sol is R 2.0, which is summer warmth by itself; two foam pads, or foam under an air pad, is the usual way to reach R 5.5.

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WildProofLab is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. R-values and weights are the makers' own.