Insulation Calculator
Turn wall, ceiling or floor areas into whole insulation packages using the coverage printed on your product.
How it works
Use the package label as the source of truth
Insulation package coverage varies by product thickness, R-value, cavity width and batt or roll dimensions. DIYSum therefore uses the coverage value you enter rather than assuming a universal package size.
Packages = (net area × allowance) ÷ package coverage
Does this choose the correct R-value?
No. Required R-values and assemblies depend on climate, location in the building and applicable energy code. Confirm those requirements separately.
Should I subtract windows and doors?
You can subtract openings, but keeping a modest extra allowance can help cover trimming and irregular cavities.