How this calculator works
Estimate the insulated wall area and the number of packages required based on the coverage printed on the product.
Formula
Net wall area = wall length × height − openings. Packages = net area × (1 + waste) ÷ package coverage.
Net wall area = wall length × height − openings. Packages = net area × (1 + waste) ÷ package coverage.
Example
An 80 ft exterior wall run at 8 ft high equals 640 sq ft before subtracting doors and windows.
Reliability check
Match package coverage to cavity width, depth and framing spacing. Area alone cannot confirm R-value, compression, vapor control, fire performance or whether professional installation is required.
How to get a better estimate
- R-value requirements vary by climate zone and assembly.
- Use the package coverage for the exact batt width and thickness.
- Do not compress insulation to force it into a cavity.
What the result means
Area alone does not select an insulation product. Confirm cavity depth, framing spacing, R-value, vapor-control requirements and the coverage printed on the selected package.