Sleeping Pad R-Values Explained

Cold campers usually blame their sleeping bag. Most of the time, the real problem is underneath them. Your body crushes the insulation in your bag, and the cold ground pulls heat out all night. That's the sleeping pad's job, and its R-value tells you how well it does it.

01What R-value means

R-value measures resistance to heat flow. The higher the number, the better the pad insulates you from the ground. It's the same idea as the R-value on house insulation.

Since 2020, most major pad makers test with the same lab standard (ASTM F3340), so R-values from different brands can finally be compared fairly. Older pads and some budget brands may still use their own methods, so treat those numbers with caution.

02What R-value you need

A rough guide many campers and brands use:

• Summer, warm nights: R 1–2
• Three-season (spring and fall, nights near freezing): about R 3–4
• Late fall and winter: R 5 and up
• Snow camping: R 6 and up

If you sleep cold, go higher. Ground temperature, not just air temperature, is what matters: frozen ground and snow pull heat fast.

03Stack them

R-values add up when you stack pads. A closed-cell foam pad (often around R 2) under an inflatable pad (say R 3) gives you about R 5. The foam pad also protects the inflatable from punctures, and if the inflatable fails at 2 a.m., you still have something under you.

04Types of pads

• Closed-cell foam: cheap, tough, can't pop, low R per inch. Great as a base layer.
• Self-inflating: foam inside an air chamber. Comfortable, mid-weight.
• Inflatable (air) pads: light and packable. Insulated versions have reflective layers or synthetic fill; uninsulated ones are cold.
• Air mattresses for car camping: comfortable but cold. All that air cools off. Put a foam pad or blankets on top.

05Fall camping tip

On nights in the 30s, aim for R 4 or higher, and pair it with the right bag. See staying warm when nights drop below 40.

The best sleeping bag in the world won't keep you warm on a thin pad. Fix what's under you first.

Photo: A person adjusting a sleeping bag inside a tent by Mike Burns, CC BY-SA 2.0.

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