Adjust the project details below to build a practical planning range. Then use the sections underneath to understand what can move the final price.
Estimate a 2026 attic insulation budget using attic area, insulation type, air sealing, old-insulation removal, and local cost level.
Calculate your attic insulation range
Climate zone and target R-value matter. This is a planning estimate, not an insulation contractor quote.
Mold, pests, asbestos, difficult access, ventilation work, and electrical changes can raise the final project cost.
2026 U.S. attic insulation benchmark
Angi reports attic insulation at about $1 to $3 per square foot overall, with an average project near $2,100. Air sealing commonly adds $250 to $750, while old insulation removal is often about $1 to $1.50 per square foot.
2026 Cost by Insulation Type
The calculator uses separate broad installed cost-per-square-foot benchmarks for each material, rather than simply multiplying one overall national average. The ranges below are from Angi’s attic insulation cost guide, updated October 12, 2026. Installation depth, target R-value, site conditions and climate affect the actual quote.
| Insulation type | Planning benchmark per sq ft |
|---|---|
| Reflective radiant barrier | $0.50–$2 |
| Blown-in | $1–$4 |
| Batt | $2–$4 |
| Loose fill | $2–$5 |
| Spray foam | $2–$5 |
Important: Reflective radiant barriers do not substitute for an adequate thermal R-value, particularly in colder climates. Spray foam proposals can vary significantly with open-cell versus closed-cell material and installed thickness; a square-foot estimate alone cannot confirm the required R-value. The air-sealing option adds an illustrative $500 allowance and old-insulation removal adds $1.25 per sq ft, in line with the published broad ranges. Check a real quote before adding these items because some installers already include part of the preparation or air-sealing work. None of these calculator settings certifies a code-compliant assembly.
What changes attic insulation cost?
Attic size, material, R-value target, climate zone, access, air sealing, removal, ventilation, pest or mold problems, and electrical conditions all affect final pricing.
Reference: Angi — Attic Insulation Cost, 2026.
How to use the attic insulation estimate
Start with attic floor area, then choose the insulation approach that best matches the project. The correct insulation depth and R-value depend on climate and the existing assembly, so a contractor may recommend a different quantity after inspecting the attic.
Attic insulation quote checklist
- Target R-value and insulation type
- Air sealing scope
- Old insulation removal, if needed
- Ventilation baffles and soffit clearance
- Electrical and recessed-light safety details
- Mold, pest, or moisture remediation exclusions
Attic insulation FAQ
How much does it cost to insulate a 1,800 sq ft attic?
Angi’s 2026 guidance gives an example of roughly $1,800 to $5,400 for a 1,800-square-foot attic before special removal, remediation, or access issues.
Should air sealing be done first?
It is often useful because sealing obvious air leaks before adding insulation can improve performance. Angi reports air sealing commonly adding about $250 to $750.
Related: Attic Insulation Cost for 1,500 Sq Ft · HVAC Replacement Cost Calculator · All calculators