Spray foam is priced per board foot - one square foot covered to one inch thick - so before you can read any quote, it helps to estimate how many board feet your job needs. This calculator turns your area and target thickness into an estimated quantity.
How to use it
- Enter the area to be sprayed (square feet).
- Enter the target thickness in inches - or pick a target R-value and let it convert (attic R-38 is about 6 inches of closed-cell or 11 inches of open-cell).
- Get an estimated board-foot quantity you can take into any conversation with an installer.
What it is - and is not
The result is an estimate for planning, not a quote. Real price depends on foam type, access, prep and your specific building, which only a site visit confirms. We never turn a calculator output into a price.
Request a quote and a vetted installer will size and price the job on your actual space. See what drives cost.
Spray Foam Board-Foot Calculator
Estimate how much spray foam your project needs — and a ballpark range. For a real, no-obligation number, get a free quote.
Estimate only — not a quote. Actual cost depends on prep, access, thickness, and site conditions. Get your real quote →