Spray Foam Insulation Cost Calculator
Board feet, sets and installed cost for open or closed cell.
Enter your values
Enter the area to insulate in sq ft.
Choose one of: Open cell (R-3.7/in), Closed cell (R-6.5/in).
Enter the target r-value in R.
Enter the price per board foot in $.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Installed cost
- $8,769.23
- Board feet
- 7,015
- Thickness needed
- 5.85 in
- Cost per sq ft
- $7.31
- DIY kits (600 bf)
- 12
Quick answer
Spray foam is priced per board foot (1 sq ft at 1 in thick); open cell runs about $0.45–0.75 and closed cell $1.00–1.50 per board foot installed.
board feet = area × thickness (in)
At a glance
| What it does | Board feet, sets and installed cost for open or closed cell. |
|---|---|
| Category | Home & DIY |
| Inputs needed | Area to insulate, Foam type, Target R-value, Price per board foot |
| Main output | Installed cost |
| Formula | board feet = area × thickness (in) |
| Cost | Free — no sign-up, no download |
How to use the Spray Foam Insulation Cost Calculator
- 1Enter the square footage of wall, roof deck or crawl space.
- 2Choose open or closed cell foam.
- 3Set your target R-value and local price per board foot.
Inputs explained
- Area to insulate(sq ft)
- Enter the area to insulate in sq ft.
- Foam type
- Choose one of: Open cell (R-3.7/in), Closed cell (R-6.5/in).
- Target R-value(R)
- Enter the target r-value in R.
- Price per board foot($)
- Enter the price per board foot in $.
Worked example
Using the values the calculator loads with:
Inputs
- Area to insulate1200 sq ft
- Foam typeClosed cell (R-6.5/in)
- Target R-value38 R
- Price per board foot1.25 $
Results
- Installed cost$8,769.23
- Board feet7,015
- Thickness needed5.85 in
- Cost per sq ft$7.31
- DIY kits (600 bf)12
Frequently asked questions
What is a board foot of spray foam?
One square foot sprayed one inch thick — the standard unit foam contractors quote on.
Is closed cell worth the extra cost?
In crawl spaces, rim joists and roof decks yes: it adds a vapour barrier and nearly double the R per inch.
What do I need to enter into the Spray Foam Insulation Cost Calculator?
Just 4 values: area to insulate, foam type, target r-value, price per board foot. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Spray Foam Insulation Cost Calculator work out the answer?
Spray foam is priced per board foot (1 sq ft at 1 in thick); open cell runs about $0.45–0.75 and closed cell $1.00–1.50 per board foot installed. It applies the formula board feet = area × thickness (in) and shows the working so you can check each step by hand.
Is the Spray Foam Insulation Cost Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.