Attic Insulation Calculator

Attic Insulation Calculator

Do you want to know how much insulation you need in your attic?  Use this calculator to find out.  After selecting your climate zone (see map below), use the buttons to first add your existing types and amounts of insulation.  Then use the lower buttons to add your new insulation types and amounts.  Add enough insulation to meet 100% of the amount listed in the International Energy Conservation Code (IECC) building code standard by checking the calculator gauge value.

Select Zone:
Select amounts of existing insulation (inches)
Cellulose (blown):  
Fiberglass (blown):  
Fiberglass (batt):  
Rock Wool (blown):  
Rock Woll (batt):  

Select amounts of insulation to add (inches)
Cellulose (blown):  
Fiberglass (blown):  
Fiberglass (batt):  
Rock Wool (blown):  
Rock Wool (batt):  
R total =

Zone Map

Source: International Energy Conservation Code (IECC)

Note: The Attic Insulation Calculator is to be used for illustration purposes only.   Although every effort was made to ensure the calculator is accurate, please check your local building codes for the most up to date insulation requirements.  The R-value by zone data is according to the 2021 International Energy Conservation Code (IECC) building code standard. Insulation R-vales used in this calculator should be considered approximate. Make sure to check the manufacturer's specifications for the actual insulation products used.