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Attic Insulation Cost Calculator
Can I DIY? · DIY-FriendlyCalculate how much attic insulation costs based on your attic size, insulation type, and R-value goal — with energy savings analysis.
Educational calculators — always consult a licensed professional before making financial decisions.
Typical for smaller ranch homes or partial attics. Covers homes under ~1,000 sq ft.
Loose fiberglass blown in place. Good coverage, non-combustible, common in older homes. R-2.2 per inch.
No existing insulation or you're unsure. Will estimate full insulation cost from scratch.
DOE minimum for warm southern climates (Climate Zones 1–3).
You can walk upright throughout. Fastest installation; no labor surcharge.
Estimated Insulation Cost
$680 – $1,264
12" of insulation needed
Cost Breakdown
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Estimates based on national averages. Actual costs vary by region and contractor.
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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 Installed |
|---|---|---|
| Blown-In Fiberglass | R-2.5 | $1.00 – $3.00 |
| Blown-In Cellulose | R-3.7 | $1.00 – $3.00 |
| Batt Fiberglass | R-3.2 | $1.50 – $3.50 |
| Spray Foam | R-6.5 | $1.50 – $7.00 |
Costs include material and labor. The federal 25C insulation credit ended after Dec 31, 2025; state and utility rebates may still apply — check DSIRE (dsireusa.org).
Methodology & sources
The cost figures on this page are generated from a single, sourced cost-data file (Per sq ft installed by type. National average estimate for 2026 (~$2,500 for a typical attic).). DOE recommends R-30 to R-60 for attics by climate zone. Blown-in is the most affordable; spray foam costs most but air-seals best. Last verified July 2026.
- HomeGuide — Attic Insulation Cost (2026) — retrieved 2026-07-13
- Angi — Attic Insulation Cost (2026) — retrieved 2026-07-13
Related Calculators
Frequently Asked Questions
How much does attic insulation cost?+
Attic insulation costs $1–$7 per sq ft installed, depending on type and R-value target. Blown-in cellulose or fiberglass costs $1–$3/sq ft. Fiberglass batts cost $1.50–$3.50/sq ft. Spray foam costs $1.50–$7/sq ft. The federal 25C insulation credit ended after December 31, 2025, but many state and utility programs still offer insulation rebates.
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 in 2026?+
No federal credit for 2026 work. The 25C Energy Efficient Home Improvement Credit — 30% of material costs up to $1,200 per year — ended for insulation placed in service after December 31, 2025 (One Big Beautiful Bill Act, 2025). Insulation installed by December 31, 2025 can still be claimed on your 2025 return (IRS Form 5695). Many states and utilities still offer insulation rebates — search DSIRE (dsireusa.org) by your ZIP.
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Attic Insulation Cost Calculator is built and maintained by the RealCostIQ editorial team. Cost ranges and rates are checked against published industry data and contractor quotes, and revised when the underlying figures move. Read our data methodology or more about who builds this. Every calculation runs in your browser — no account, and none of your inputs are stored.
Cost ranges and rates here are checked against contractor quotes and published industry data. If a number still looks off, email Support@RealCostIQ.com and we'll review and fix it.