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Insulation Calculator

Calculate insulation for attic, walls, or crawl space.

Inputs

$

Total Area

0 sqft

Bags/Rolls

0

Estimated Cost

$0

How to Use This Insulation Calculator

Our free insulation calculator determines how much insulation you need for your attic, walls, or crawl space. Enter your area dimensions and desired R-value for material quantities and cost estimates.

R-value measures thermal resistance — higher numbers mean better insulation. Recommended values vary by climate zone. Our calculator suggests appropriate R-values for your location.

The calculator compares blown-in vs batt insulation options. Blown-in is better for irregular spaces; batts are cost-effective for new construction.

Related Topics

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Frequently Asked Questions about Home Insulation

How much insulation do I need for my attic?

Measure attic floor area. Most climates need R-38 to R-60, which is 12-20 inches of blown fiberglass.

What R-value should my insulation be?

Depends on climate zone. Zones 1-2: R-30 to R-49. Zones 3-4: R-38 to R-60. Zones 5-7: R-49 to R-60.

How much does insulation cost per sq ft?

Blown fiberglass: $1-$2 per sq ft for R-30. Cellulose: $1-$1.50. Fiberglass batts: $0.50-$1.

What is the difference between blown-in and batt insulation?

Blown-in fills irregular spaces. Batts fit between studs. Blown-in is better for attics; batts for new construction.

Do I need a vapor barrier with insulation?

In cold climates, vapor barrier goes on the warm side. In hot humid climates, on the exterior side. Check local codes.