How much insulation do I need?

Measure the area and target the right R-value — R-38 to R-60 in attics and R-13 to R-21 in walls, depending on climate.

What is the cheapest insulation?

Fiberglass batts have the lowest installed cost; blown-in is best for attics and retrofits.

Insulation Calculators

Cut energy bills with the right amount of insulation. Our insulation calculators turn your wall or attic area into material and installed-cost estimates for fiberglass batts, blown-in cellulose, and spray foam — with the R-value targets for your climate. Explore the tools and cost guides below.

Insulation calculators

Insulation Calculator

Estimate the square footage, material, and cost to insulate walls or an attic by insulation type.

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What you can estimate

Square footage to insulate
Cost by insulation type
R-value targets for walls and attics
Batt, blown-in, and spray foam pricing

Insulation FAQs

Explore more categories

Drywall

Siding