Insulation Calculator will help you quickly estimate the cost of insulation your attic space, using either Closed or Open Cell Spray Foam, Fiberglass/Mineral Wool (Rolled or Batt), Blown-In Insulation (Fiberglass or Cellulose), based on required R-Value or Stud/Rafter size.
Prices can be calculated just for installing insulation between Ceiling Joists, or to make the whole attic insulated (including walls and Roof Rafters), based on your attic size, framing, insulation material, and how much R-Value you need/want.
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NOTE: If you select blown-in insulation, the calculator will automatically switch to ONLY insulating between ceiling joists, as blown-in insulation cannot be installed between roof rafters.
If you select to insulate the entire attic space (including rafters and/or walls), the material will be switched to Closed Cell spray foam. You can than change the material to your desired type.
This is done to prevent the calculator for producing inaccurate results.
How Much Does Attic Insulation Cost?
Attic insulation costs range from $1.79 per square foot for Blown In Insulation to $4.34 per square foot for Closed Cell Spray Foam Insulation, at 38R-value, which is a new Building Code requirement for Roofs/Ceilings in most states.
Attic Insulation Cost Per Square Foot
The chart below provides attic insulation cost estimates based on the number of square feet in your attic.
You can see how much it costs to insulate 1,000, 1,500 and 2, 000 sq.ft. of attic space.
| Area (at 38R-value) | Blown-in Cost | Closed Cell Spray Foam Cost |
|---|---|---|
| 500 s.f. | $895 | $2,170 |
| 1000 s.f. | $1,790 | $4,340 |
| 1,500 s.f. | $2,685 | $6,510 |
| 2,000 s.f. | $3,580 | $8,680 |
| 2,500 s.f. | $4,475 | $10,850 |
How Do I Calculate Attic Insulation?
In most cases, people only insulate between ceiling joists, to reduce heat loss.
If you are looking to insulate the entire attic (to either have a finished attic later, or any other reason, select “Roof / Walls” in the Areas to Insulate section.
This will enable additional options, such as roof rafter and wall stud sizes, windows/skylights, roof type (Hip or Gable), etc, and will assume the your entire attic will be either finished or heated, and otherwise habitable.
PRO TIP: This calculator is designed to estimate costs of Attic Insulation only. If you need to calculate prices of insulating your whole house, use our Spray Foam Calculator.
Our whole house insulation calculator will sum up total square footage of all walls, roof structure, subtract openings such as doors and windows, and calculate total required thickness (R-Value) of insulation needed, as well as provide estimate installation (labor + materials) cost.
What R Value Do I Need In An Attic?
For most attics, pros recommend insulating up to R-38 or about 10 to 14 inches. However, this depends on the insulation type you choose as well as other factors in your attic.
How Much Can I Save By Insulating the Attic?
Insulation helps reduce heat transfer from the conditioned spaces in your house to the unconditioned outside.
As a result, your home’s warm air will escape more slowly when you have the heat on during the cold months. On the other hand, during the summer months, your house will stay cooler longer, when run your AC.
Pro Tip: According to the Department of Energy, properly insulating your attic can save as much as 10-50% off your heating bill.
In the areas with prolonged winters and very high heating costs, insulating your attic can be a very fast and reliable way to increase the comfort in your home, and significantly reduce monthly spending on heat.
Can You Have Too Much Insulation?
When it come to insulation, more does not always mean better. For most homes, in most regions going past R-38 for attic insulation is an unnecessary investment, and can even be detrimental in some cases.
First, over-insulating will not improve your home’s energy efficiency.
Second, you will not be seeing enough of a return on investment if you spend too much money to on attic insulation.
Lastly, putting to much insulation in a vented attic can actually be harmful, because it will prevent proper air circulation.
When insulating your attic, its best to focus on the correct placement of the insulation as well as the quality of installation. These two factors can make a huge difference in bringing your attic to optimal energy efficiency.
