Insulation Calculator
Use this free insulation calculator to estimate the total cost of insulating your attic, walls, floor, or basement. Select your insulation type — fiberglass batt, blown-in cellulose, spray foam, mineral wool, or rigid foam board — enter your area dimensions, and get an instant cost range based on 2026 US average pricing.
× (Material + Labor) Cost per sq ft
Fiberglass Batt $0.30–$0.65/sq ft · Mineral Wool $0.60–$1.20/sq ft · Blown Fiberglass $0.50–$1.00/sq ft · Cellulose $0.40–$0.80/sq ft · Open Cell Spray Foam $0.50–$1.00/sq ft · Closed Cell $1.00–$2.50/sq ft · Rigid Foam $0.50–$1.50/sq ft (material only)
Estimates based on 2026 US average pricing. Costs vary by R-value, thickness, and region. Always get 3 quotes.
How Does the Insulation Calculator Work?
This insulation calculator estimates the total cost of insulating any area of your home based on square footage, insulation type, installation location, and whether you hire a contractor or install it yourself. It uses 2026 US average pricing across 7 common insulation types and automatically adds a 10% waste allowance.
Steps:
- Enter the length and width of the area you want to insulate in feet.
- Select your insulation type — fiberglass batt, mineral wool, blown-in, spray foam, or rigid foam board.
- Select the installation location — attic, walls, floor/crawl space, or basement.
- Choose DIY or Contractor to include or exclude labor costs.
- Get instant results — total cost range, area, material cost, and labor cost.
R-value measures an insulation material's resistance to heat flow. The higher the R-value, the better the insulation. Required R-values vary by climate zone and location in your home — see the R-value chart below to find what's recommended for your area.
R-Value Chart by Climate Zone
The US Department of Energy recommends different R-values depending on your climate zone and where you're insulating. Use this chart to find the right R-value for your project.
| Climate Zone | States (Examples) | Attic | Walls | Floor |
|---|---|---|---|---|
| Zone 1–2 (Hot) | FL, HI, TX (south) | R-30 – R-49 | R-13 | R-13 |
| Zone 3 (Warm) | GA, AL, CA (south) | R-30 – R-60 | R-13 – R-15 | R-19 – R-25 |
| Zone 4 (Mixed) | TN, VA, OR, WA | R-38 – R-60 | R-13 – R-21 | R-25 – R-30 |
| Zone 5 (Cool) | IL, OH, PA, CO | R-49 – R-60 | R-15 – R-21 | R-25 – R-30 |
| Zone 6–7 (Cold) | MN, WI, MT, ND | R-49 – R-60 | R-19 – R-21 | R-25 – R-30 |
*Source: US Department of Energy insulation recommendations. Check energystar.gov for your specific zip code.
Fiberglass batt: R-3.2/in · Mineral wool: R-3.7/in · Blown cellulose: R-3.5/in · Open cell spray foam: R-3.7/in · Closed cell spray foam: R-6.5/in · Rigid foam (XPS): R-5/in · Rigid foam (polyiso): R-6.5/in
Insulation Cost by Type (2026)
Insulation costs vary significantly by material and installation method. Here's a full breakdown of 2026 US average pricing per square foot for materials and professional installation.
| Type | Material $/sq ft | Installed $/sq ft | 1,000 sq ft Total | Best For |
|---|---|---|---|---|
| Fiberglass Batt | $0.30 – $0.65 | $0.64 – $1.20 | $640 – $1,200 | Walls, attics, DIY |
| Blown-In Cellulose | $0.40 – $0.80 | $0.80 – $1.50 | $800 – $1,500 | Attics, retrofit walls |
| Blown-In Fiberglass | $0.50 – $1.00 | $1.00 – $1.80 | $1,000 – $1,800 | Attics, hard to reach areas |
| Mineral Wool Batt | $0.60 – $1.20 | $1.20 – $2.00 | $1,200 – $2,000 | Walls, fire resistance |
| Rigid Foam Board | $0.50 – $1.50 | $1.50 – $3.00 | $1,500 – $3,000 | Basement walls, exterior |
| Spray Foam (Open Cell) | $0.50 – $1.00 | $1.50 – $3.00 | $1,500 – $3,000 | Walls, crawl spaces |
| Spray Foam (Closed Cell) | $1.00 – $2.50 | $3.00 – $6.50 | $3,000 – $6,500 | Moisture barriers, rooflines |
*Installed cost includes labor. Prices vary by thickness/R-value required. Spray foam requires professional installation.
Attic: Blown-in cellulose or fiberglass — cheap, fast, and effective. Walls: Fiberglass batt for new construction; blown-in cellulose for existing walls. Basement/crawl space: Rigid foam or closed cell spray foam for moisture resistance.
Example Calculation
You want to insulate a 40 ft × 30 ft attic with blown-in cellulose, hired contractor.
40 ft × 30 ft = 1,200 sq ft
Step 2 — Add 10% waste:1,200 × 1.10 = 1,320 sq ft material needed
Step 3 — Material cost (cellulose $0.40–$0.80/sq ft):1,320 × $0.40 = $528 | 1,320 × $0.80 = $1,056
Material: $528 – $1,056
1,200 × $0.40 = $480 | 1,200 × $0.70 = $840
Labor: $480 – $840
$1,008 – $1,896
Factors That Affect Insulation Cost
R-Value Required
Higher R-values require more material or thicker installation — directly increasing cost. An attic requiring R-60 costs roughly twice as much as one requiring R-30 for the same square footage.
Existing Insulation Removal
If old insulation needs to be removed (damaged, moldy, or pest-infested), removal adds $1–$2 per sq ft. For a 1,000 sq ft attic that's an extra $1,000–$2,000 before new insulation is installed.
Accessibility
Hard-to-reach areas like low attics, tight crawl spaces, or finished walls increase labor time and cost. Expect 20–40% higher labor costs for difficult access locations compared to open, easy-access areas.
Air Sealing
Air sealing (caulking and foam around gaps, penetrations, and bypasses) should be done before insulating for maximum energy efficiency. Air sealing adds $0.25–$0.75 per sq ft but can improve energy savings by 15–30% compared to insulation alone.
Region & Climate
Labor costs in high cost-of-living areas run 25–40% higher than the national averages. Colder climates also require higher R-values, meaning more material — both factors increase the total project cost in northern states.
The federal Inflation Reduction Act offers tax credits of up to 30% (max $1,200/year) for qualifying insulation improvements. Many state and utility programs offer additional rebates. Check energystar.gov/rebates before starting your project — you may save hundreds.