Insulation Calculator

Keeping your home well insulated is the key to keeping your energy bills in check. To find out the square footage of insulation you need for your home, just tell us the size of each area you need to insulate, your heating type and the area where you live, then hit the "Calculate Now" button to tabulate your results. To determine the number of bags of insulation you need, take your square footage requirements to your local Home Depot for help based on the manufacturer's brand.

Calculator Inputs

Wall Dimensions

(also for: slab edge and interior/exterior basement)

Wall 1 Length: ft. in.
Wall 1 Height: ft. in.
Wall 2 Length: ft. in.
Wall 2 Height: ft. in.
Wall 3 Length: ft. in.
Wall 3 Height: ft. in.
Wall 4 Length: ft. in.
Wall 4 Height: ft. in.

Attic/Ceiling Dimensions

(also for: floor/crawl space)

Width: ft. in.
Length: ft. in.


Number of Windows:  
Window Height: ft. in.
Window Width: ft. in.


Number of Doors:  
Doors Height: ft. in.
Doors Width: ft. in.

If you have windows or doors with different heights and widths, average the window or door dimensions. For example, one 1 x 1 window and one 2 x 1 window would be approximately two 1.50 x 1 windows.

Primary Heat Source

(select one)

Electric Furnace    Gas    Heat Pump    Fuel Oil

Insulation Zone

Find where you live, then click the corresponding zone below.

Insulation Zone Map

  • Zone 1 color Zone 1
  • Zone 2 color Zone 2
  • Zone 3 color Zone 3
  • Zone 4 color Zone 4
  • Zone 5 color Zone 5
  • Zone 6 color Zone 6
  • Zone 7 color Zone 7 (Canada)

(Map provided by the U.S. Department of Energy)

To complete this project, you may also need: vapor barrier, dust mask, staple guns, utility knives, goggles, insulation supports, and gloves.

For more expert advice on insulation projects from Owens Corning,click here.

Calculator Results

Wall: 0 Sq. Feet
Recommended Insulation R-Values
Cath. Ceiling:
Crawl Space:
Slab Edge:
Int. Basement:
Ext. Basement:

Other Calculators


Important Disclaimer: This calculator is provided for general information and illustration purposes only; the results are to be used only as estimates and are not intended as definitive advice or as a resource applicable to any specific circumstance and should not be relied upon or used as such. The Home Depot cannot guarantee that you will achieve proper results without verifying your measurements and assumptions. For specific advice regarding your project, you should engage the services of an associate in your local Home Depot store.