Insulation for 100 sq ft
5 percent waste. Check package coverage.
Area with waste
105sq ft
Packages (40 sq ft)
3
packages = 100 × 1.05 ÷ coverage per package
About 9.3 m². Use your product coverage.
Open the Insulation CalculatorAbout this estimate
Insulation is sold by area coverage, which depends on the product. Read the coverage on the bag or roll, then divide your area by it. This page assumes 40 square feet per package as an example.
Cutting batts? A sharp utility knife with spare blades cuts fibreglass and mineral wool cleanly.
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Common questions
How much insulation for 100 square feet?
With 5 percent waste, about 105 square feet. At 40 square feet per package, that is 3 packages.
Does R value change how much I buy?
Not the package count for a given area. R value sets the thickness and price, while coverage per package sets how many you buy.
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