Attic Insulation Cost Calculator
Calculate how much attic insulation costs based on your attic size, insulation type, and R-value goal. Includes tax credit analysis.
How It Works
Measure your attic
Enter the attic floor area in square feet — typically matches your home footprint.
Set current and target R-value
Most climate zones target R-49 to R-60. Older homes often have R-11 or less.
Choose insulation type
Select blown-in cellulose, fiberglass, or batt insulation to see cost and payback.
Attic Insulation Cost by Type
| Type | R-Value/Inch | Cost/Sq Ft (R-49) |
|---|---|---|
| Blown-In Fiberglass | R-2.5 | $2.00 – $3.50 |
| Blown-In Cellulose | R-3.7 | $1.80 – $3.00 |
| Spray Foam | R-6.5 | $4.00 – $7.00 |
| Batt Fiberglass | R-3.2 | $2.00 – $3.50 |
| Mineral Wool Batt | R-3.7 | $3.00 – $5.50 |
Costs include material and labor. Tax credit of up to $1,200 available.
Frequently Asked Questions
How much does attic insulation cost?
Attic insulation costs $1.80–$7.00 per sq ft depending on type and R-value target. Blown-in cellulose to R-49 costs $1.80–$3.00/sq ft. Blown-in fiberglass to R-49 costs $2.00–$3.50/sq ft. Spray foam costs $4.00–$7.00/sq ft. A typical 1,000 sq ft attic costs $1,800–$5,000 installed. The federal tax credit covers 30% of costs up to $1,200.
What R-value should my attic insulation be?
The DOE recommends R-38 to R-60 for attics depending on climate zone. Zone 1–2 (South): R-38. Zone 3–4 (Mid-Atlantic, Midwest): R-49. Zone 5–7 (North, Mountain): R-49 to R-60. Most older homes have R-11 to R-19, far below recommendations. Adding insulation from R-11 to R-49 typically reduces heating and cooling costs by 15–25%.
What is the best attic insulation type?
Blown-in cellulose is the most cost-effective for existing attics — it achieves high R-values, uses recycled content, and resists air infiltration well. Blown-in fiberglass is also excellent. Spray foam provides the highest performance but costs 2–3x more. Batts are best for new construction with easy access. For most homeowners, blown-in cellulose or fiberglass offers the best value.
Is attic insulation eligible for a tax credit?
Yes — attic insulation qualifies for the federal Energy Efficient Home Improvement Credit: 30% of material costs (not labor) up to $1,200 per year. The insulation must meet the IECC standards in effect at the time. Blown-in insulation, batts, and rigid foam all qualify. Claim the credit on IRS Form 5695. Some states and utilities also offer additional rebates.
Get your personalized estimate
Answer 5 questions for a cost range tailored to your attic.
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