Attic Insulation Calculator
Estimate added attic-insulation thickness, volume, packages and cost from attic area, current R-value, target R-value and product coverage.
Default project preview
12.4 in
Added R-value
R-36
Base added depth
11.3 in
Packages
289
Installed volume index
17,325 ft²·in
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Added R-value = target − current. Base depth = added R-value ÷ product R per depth unit. Apply settlement allowance. Packages = round up (attic area × order depth ÷ package coverage index).
Related tools
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BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Attic Insulation Calculator questions
Why must product coverage be entered at one depth unit?+
Blown and batt products have different package yields. A coverage index lets package quantity scale with the required installed depth.
Should old insulation be removed?+
Not always. Existing insulation condition, contamination, moisture, air leakage and access determine whether it can remain.
Does this choose the correct target R-value?+
No. The target is editable because climate, assembly and local energy requirements vary.