SettingsSettings for this calculationUS
The total surface area to cover.
Measure the wall, ceiling, or rim-joist area to be sprayed.
How thick a layer to spray.
1-2 in (25-50 mm) is typical for rim joists and small gaps; open-cell insulation for full wall cavities is often sprayed 3-5+ in (75-125 mm) thick to fill the cavity.
Spray foam needed
1 x 600 bd-ft kit
Kit coverage varies by brand and ambient temperature/humidity during application — check your specific kit's published coverage chart before buying.
- Foam volume needed
- 220 board ft
They open the calculator with your figures already in it
Spray Foam Insulation Calculator: 1 600 bd-ft kit — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Board feet = area (sq ft) x thickness (in); a standard DIY 2-part spray foam kit covers approximately 600 board feet at 1 in thickness in North America. Board foot is a US trade volume (1 bd ft = 0.00236 m³, so a 600 bd-ft kit yields about 1.42 m³) with no metric counterpart in use and no equivalent standard kit size, so on metric the answer is given as the volume of foam required rather than a kit count
Inputs used
- Area to Insulate
- 220 sq ft
- Application Thickness
- 1 in
Intermediate steps
- Foam volume needed
- 220 board ft
Confidence note: Kit coverage varies by brand and ambient temperature/humidity during application — check your specific kit's published coverage chart before buying.
What this calculation does not cover
- The figure is the raw geometric volume of the space — area times thickness — with nothing added for overspray, foam trimmed back flush, hose purge, or material stranded in a spent tank. Published kit yields are ideal-condition maximums; cold tanks or a cold substrate deliver less than the rating.
- Area is taken as gross surface. Studs, joists, rafters and blocking are not deducted, and nothing is allowed for working around wiring, boxes and pipework, so a clear bay and a congested one produce the same number.
- This is a quantity take-off, not a thermal or code check. It returns no R-value, and it does not test the thickness you enter against a code requirement or against the depth of the cavity you are filling. Open-cell and closed-cell foam are nowhere near the same R per inch, so the same thickness is not the same performance.
- It does not cover how the foam goes on. Closed-cell has to be built up in passes rather than one deep lift, cured foam left exposed generally needs a thermal or ignition barrier over it to satisfy code, and two-part kits require respiratory protection and a re-occupancy period before the space is used.
- Where foam belongs in the assembly is a separate decision. Whether a roof can be unvented, whether a rim joist or wall needs vapour control, and where the dew point lands in the finished build-up are not questions this take-off answers.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Part of a bigger job
This trade is one line of a job takeoff. Run the whole job and every other trade comes back with it, off the same measurements.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-05 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Board feet = area (sq ft) x thickness (in); a standard DIY 2-part spray foam kit covers approximately 600 board feet at 1 in thickness in North America. Board foot is a US trade volume (1 bd ft = 0.00236 m³, so a 600 bd-ft kit yields about 1.42 m³) with no metric counterpart in use and no equivalent standard kit size, so on metric the answer is given as the volume of foam required rather than a kit count
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Your workspace
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