Home & DIY CalculatorsPrivate by design
Insulation R-Value Calculator
Add each insulation layer's material and thickness to calculate your total combined R-value.
How to use this tool
- 1Choose a material preset or enter a custom R-value per inch.
- 2Enter that layer's thickness.
- 3Add more layers as needed.
- 4See your total R-value.
Frequently asked questions
Do R-values just add up?+
Yes — R-values add directly in series when layers are stacked, which is why combining batt insulation with rigid foam board increases total R-value.
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