Cost Calculator AI
Construction & ContractorsR-Value Energy Tool

Insulation Cost Calculator

Calculate fiberglass batts, blown-in cellulose, and spray foam insulation costs for attics, walls, and crawlspaces by target R-value.

Calculation Results

Insulation Cost & Energy Savings Formula

Total Cost = Surface Area sq ft × Target R-Value × Rate per R + Professional Labor
  • Recommended R-Values: Attics (R-38 to R-49), 2x4 Walls (R-13 to R-15), 2x6 Walls (R-19 to R-21), Floors (R-25 to R-30).
  • Material Types: Fiberglass batts (economical DIY), Blown-in cellulose (best attic coverage), Closed-cell spray foam (maximum R-value & vapor barrier).
  • Energy Payback: Upgrading attic insulation typically reduces annual heating/cooling bills by 15%.

Step-by-Step Worked Example

Scenario: Insulating a 1,400 sq ft attic to R-38 using blown-in cellulose with professional labor

Calculation Steps:

  1. Material Cost = 1,400 sq ft × 38 × $0.032/R = $1,702.40
  2. Installation Labor = 1,400 sq ft × $0.70 = $980.00
  3. Total Installed Cost = $1,702.40 + $980.00 = $2,682.40
  4. Cost Per Square Foot = $2,682.40 / 1,400 = $1.92 / sq ft
  5. Estimated Annual Energy Savings = 1,400 × $0.22 = $308 / year
Result: Installed cost is $2,682 ($1.92/sq ft), generating an estimated $308 in annual energy bill savings.

How to Use This Calculator

  1. 1Enter the square footage of the space to insulate.
  2. 2Select the application area, insulation material, and target R-value.

Assumptions & Limitations

  • Estimates are based on standard national averages and current prevailing construction materials and contractor rates.
  • Actual trade bids may fluctuate according to local building code requirements, permit fees, and site topography.
  • Always obtain multiple written bids from licensed, bonded, and insured contractors before commencing work.

Frequently Asked Questions

What is R-value in insulation?

R-value measures thermal resistance—the material’s resistance to conductive heat flow. The higher the R-value, the greater the insulating power and energy savings.

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