Spray Foam Insulation Cost Calculator
Quick answer: For 1,000 square feet, open-cell foam at about R-13 typically costs $1,250 to $2,500, and closed-cell foam at about R-20 costs $3,250 to $5,750. Attics and crawl spaces in existing homes cost more.
Estimate spray foam insulation cost for open-cell or closed-cell foam. Enter the area for a low, typical and high installed price and cost per sq ft.
Estimated total
- Low
- $1,250
- Typical
- $1,750
- High
- $2,500
$1.75 per sq ft all-in (range $1.25–$2.50)
Where the money goes (typical)
- Materials
- $875 (50%)
- Labor
- $875 (50%)
Line items (typical)
| Open-cell, 3.5 in (about R-13) | $1,750 |
Fills a 2 × 4 wall cavity. Soft, sound-deadening, lets moisture pass.
General U.S. estimates for installed cost, not quotes. We compared them with national ranges from HomeGuide (about $1.50–$3.50 per sq ft for open-cell and $3–$5 for closed-cell), HomeAdvisor and Angi. Prices reviewed November 2026. Get at least three local quotes before you commit.
Spray foam is priced by the board foot (one square foot, one inch thick) or by the square foot at a set thickness. Open-cell foam is cheaper per inch but needs more depth for the same R-value; closed-cell foam costs more but packs about twice the R-value into each inch and blocks moisture.
Enter the area you want sprayed, choose the foam type and thickness, and add removal or a thermal barrier if needed. You get a realistic installed range, the labor and material split, and the cost per square foot.
How the spray foam insulation cost estimate works
- Enter the area to spray in square feet.
- Multiply it by the installed price per sq ft for the material you chose.
- Adjust for where the foam goes and your local cost level.
- Add the extras you ticked, such as removal, and any permit fee.
- Show the result as a low, typical and high total, split into materials, labor and fees.
For walls, multiply wall length by height. For an unvented attic the foam goes on the underside of the roof deck, which is 10% to 30% larger than the attic floor, so measure the roof slopes and gable walls.
Spray Foam Insulation Cost by material
| Material | Installed per sq ft | Labor share | Notes |
|---|---|---|---|
| Open-cell, 3.5 in (about R-13) | $1.25–$2.50 | 50% | Fills a 2 × 4 wall cavity. Soft, sound-deadening, lets moisture pass. |
| Open-cell, 5.5 in (about R-20) | $2.00–$3.75 | 50% | Typical depth under a roof deck for an unvented attic in mild climates. |
| Closed-cell, 2 in (about R-13) | $2.25–$4.00 | 45% | Rigid, adds strength and acts as a vapor barrier. Good for basements and rim joists. |
| Closed-cell, 3 in (about R-20) | $3.25–$5.75 | 45% | Highest R-value per inch. Used on roof decks and crawl space walls. |
Spray Foam Insulation Cost by size
Typical total with the low–high range below it. Assumes open walls or new construction; average u.s..
| Area to spray | Open-cell, 3.5 in (about R-13) | Open-cell, 5.5 in (about R-20) | Closed-cell, 2 in (about R-13) | Closed-cell, 3 in (about R-20) |
|---|---|---|---|---|
| 250 sq ft | $450$300–$650 | $700$500–$950 | $750$550–$1,000 | $1,050$800–$1,450 |
| 500 sq ft | $900$650–$1,250 | $1,400$1,000–$1,900 | $1,500$1,150–$2,000 | $2,150$1,650–$2,900 |
| 1,000 sq ft | $1,750$1,250–$2,500 | $2,750$2,000–$3,750 | $3,000$2,250–$4,000 | $4,250$3,250–$5,750 |
| 1,500 sq ft | $2,650$1,900–$3,750 | $4,150$3,000–$5,650 | $4,500$3,400–$6,000 | $6,400$4,900–$8,650 |
| 2,000 sq ft | $3,500$2,500–$5,000 | $5,500$4,000–$7,500 | $6,000$4,500–$8,000 | $8,500$6,500–$11,500 |
What affects spray foam insulation cost
- Foam type and thickness. Cost scales with board feet. Closed-cell foam costs roughly twice as much per board foot as open-cell, and thicker layers cost proportionally more.
- New or existing home. Open stud walls in new construction are fastest. Existing attics and crawl spaces need more prep, masking and awkward work, which raises labor.
- Removal and prep. Old fiberglass or cellulose must come out before spraying a roof deck, and surfaces must be clean and dry.
- Code requirements. Foam left exposed in living areas, attics or crawl spaces usually needs an ignition or thermal barrier coating to meet fire code.
- Job size. Spray rigs have setup costs, so small jobs often carry a minimum charge. Larger areas cost less per square foot.
Frequently asked questions
How much does spray foam insulation cost?
For 1,000 square feet, open-cell foam at about R-13 typically costs $1,250 to $2,500, and closed-cell foam at about R-20 costs $3,250 to $5,750. Attics and crawl spaces in existing homes cost more.
How much is spray foam per square foot?
Open-cell runs about $1.25 to $3.75 per square foot depending on thickness, and closed-cell about $2.25 to $5.75. Per board foot, open-cell is roughly $0.35 to $0.70 and closed-cell $1 to $2.
Is open-cell or closed-cell spray foam better?
Closed-cell gives more R-value per inch, resists moisture and adds rigidity, so it suits basements, crawl spaces and tight roof bays. Open-cell is cheaper, quieter and fine for interior walls and roof decks in mild climates.
Is spray foam worth it compared with fiberglass?
Spray foam costs two to four times more but also air seals. It pays off most where air leaks are a big problem, or where you want a sealed attic with HVAC ducts inside it.
How much does it cost to spray foam an attic?
A typical attic roof deck of 1,200 to 1,500 square feet runs about $2,800 to $6,500 in open-cell and $4,500 to $10,000 in closed-cell, depending on thickness and access.
About these figures
General U.S. estimates for installed cost, not quotes. We compared them with national ranges from HomeGuide (about $1.50–$3.50 per sq ft for open-cell and $3–$5 for closed-cell), HomeAdvisor and Angi. Last reviewed November 2026. Your price depends on your home, your region and the contractor, so treat this as a budget range and compare it with written quotes.