Insulation R-Value Calculator by Climate Zone
Find the recommended insulation R-values for your home based on the U.S. Department of Energy (DOE) climate zones. Select your zone or enter your ZIP code to get guidance for walls, attics, floors, and basements.
Understanding Insulation R-Values and Climate Zones
An insulation's R-value measures its resistance to heat flow. The higher the R-value, the better the material insulates. The U.S. Department of Energy divides the country into eight climate zones to provide tailored insulation recommendations, balancing heating needs in cold climates with cooling needs in hot climates.
Using the correct R-value for your zone and home application (attic, wall, etc.) is crucial for energy efficiency, comfort, and meeting building codes. This tool provides the DOE-recommended values to help you plan your insulation project.
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Privacy Note
This calculator runs entirely in your browser. Your ZIP code and selections are not sent to any server; all calculations are performed locally on your device for your privacy.
Frequently Asked Questions
What is a good R-value for attic insulation?
A good R-value for attic insulation depends heavily on your climate zone. In warmer zones (1-3), R30 to R49 is typical. In colder zones (4-8), R49 to R60 or higher is recommended by the U.S. Department of Energy to prevent significant heat loss.
How do I find my climate zone for insulation?
The U.S. is divided into eight climate zones (1-8) for insulation purposes, based on heating and cooling degree days. You can find your zone using the DOE climate zone map, by entering your ZIP code into our calculator, or by selecting your general region from a list of states.
What is the recommended R-value for exterior walls?
Recommended R-values for exterior walls range from R13 to R21 in warmer climates (Zones 1-3) and from R21 to R30+ in colder climates (Zones 4-8). Modern energy codes often require higher values, so always check your local building department's specific requirements.