Insulation Calculator for Attics
Estimate insulation packages for an attic.
Attics need the most insulation in a house — commonly R-38 to R-60. Measure the attic floor area and enter the coverage printed on your batt or roll packages below. Higher R-value batts are thicker but cover the same floor area.
Insulation Calculator
Estimate how much you need — and the cost.
- sq meters 9.75
Tip: Lay attic batts perpendicular over the joists for a second, gap-free layer that boosts the total R-value.
How it's calculated
Batt and roll packages list the area they cover — often 40–90 sq ft depending on R-value and width. Packages = area × (1 + waste) ÷ coverage per package.
See the full Insulation Calculator for the complete how-to, unit conversions, and data sources.
Insulation Calculator for Attics FAQ
What R-value do I need for an attic?
Most climates call for R-38 to R-60 in the attic. Check your local code and climate zone for the target.
How much insulation for an attic?
Measure the attic floor area and divide by the coverage per package. Enter that coverage above for the package count.