R-value
noun
: a measure of resistance to the flow of heat through a given thickness of a material (such as insulation) with higher numbers indicating better insulating properties compare u-value
Examples of R-value in a Sentence
Recent Examples on the Web
Look for a sleeping pad with an R-value of five or higher.
—
Kaelyn Lynch, Outside, 23 Jan. 2026
Pick insulation with the right R-value for your climate; fiberglass is the easiest and most affordable choice.
—Timothy Dale, The Spruce, 17 Jan. 2026
Insulation is identified and labeled by R-value.
—Sarah Moore, Freep.com, 12 Dec. 2025
Most experts agree the R-value of attic insulation should be at least R-30 (R-38 is preferable in northern climates).
—Chad Murphy, The Enquirer, 2 July 2025
This backpacking-ready pad is made with reflective insulation, earning a three-season R-value of 3.2.
—Drew Zieff, Outside Online, 22 May 2025
An R-value of 5 or above is great for winter camping.
—Emily Pennington, Condé Nast Traveler, 13 Nov. 2023
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Kaelyn Lynch, Outside, 23 Jan. 2026
Pick insulation with the right R-value for your climate; fiberglass is the easiest and most affordable choice.
—Timothy Dale, The Spruce, 17 Jan. 2026
Insulation is identified and labeled by R-value.
—Sarah Moore, Freep.com, 12 Dec. 2025
Most experts agree the R-value of attic insulation should be at least R-30 (R-38 is preferable in northern climates).
—Chad Murphy, The Enquirer, 2 July 2025
This backpacking-ready pad is made with reflective insulation, earning a three-season R-value of 3.2.
—Drew Zieff, Outside Online, 22 May 2025
An R-value of 5 or above is great for winter camping.
—Emily Pennington, Condé Nast Traveler, 13 Nov. 2023
Cite this Entry
“R-value.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/R-value. Accessed 3 Feb. 2026.
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