Insulation R-Value Calculator
Compare how well a material insulates. Pick the material and a thickness to get the layer's R-value (thermal resistance) and U-value — and see the thickness needed to hit a target R.
Higher R = better. Foams reach a target R in less thickness than wools.
50 mm of XPS board (k = 0.03 W/m.K).
R = thickness / k for the insulation layer only. The whole-wall or whole-roof U-value also counts the other layers, surfaces and any air gaps.
Indicative only. Thermal conductivity varies with density, grade, moisture and brand, and this covers a single layer — not the full envelope, thermal bridging or condensation risk. For an ECBC or green-rating submission, confirm the build-up and U-values with your architect or an energy consultant.
Related Guides — Deep-dive reading
Building Insulation Materials Guide (India): Types, R-Value & How to Choose (2026)
The complete anchor guide to building insulation in Indian homes - why it matters, the physics in plain terms, where insulation goes, and a side-by-side comparison of every material family with clear guidance on how to choose the right one.
Building MaterialsGlass Wool Insulation in India: Properties, Uses & How to Specify It (2026)
The most common building insulation in India, decoded - what glass wool is, its thermal and acoustic strengths, the rolls and batts you can buy, where it belongs (false ceilings, AC ducts, PEB roofs, drywall) and how it compares with rock wool and foam.
Building MaterialsRock Wool Insulation in India: Fire-Rated Thermal & Acoustic Insulation Guide (2026)
What rock wool (stone mineral wool) is, why it beats most insulants on fire and sound, the forms and densities it comes in, where it wins over glass wool and foams, indicative cost and safe fibre handling - a specify-and-select guide.
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