Spray Foam Insulation Cost Calculator
Estimated Total Cost
$2,100 – $3,375
$4.20 – $6.75 per sq ft
Material
$1,725 – $2,625
Labor
$375 – $750
R-Value
R-19.5
Board Feet
1,500
Disclaimer: Estimates are for budgeting purposes only. Actual costs vary by location, contractor, material availability, and project complexity. Always get professional quotes for exact pricing.
Spray Foam Cost Breakdown
| Foam Type | Material / Board Ft | Labor / Sq Ft | R-Value / Inch |
|---|---|---|---|
| Closed-Cell | $1.15 – $1.75 | $0.75 – $1.50 | R-6.5 |
| Open-Cell | $0.44 – $0.65 | $0.50 – $1.00 | R-3.7 |
Average Project Costs by Area (Closed-Cell, 3" Thick)
| Area | Board Feet | Estimated Total |
|---|---|---|
| 200 sq ft | 600 | $840 – $1,350 |
| 500 sq ft | 1,500 | $2,100 – $3,375 |
| 1,000 sq ft | 3,000 | $4,200 – $6,750 |
| 1,500 sq ft | 4,500 | $6,300 – $10,125 |
| 2,000 sq ft | 6,000 | $8,400 – $13,500 |
How We Calculate
Our spray foam insulation calculator uses board feet as the base unit — the industry standard for quoting spray foam jobs. One board foot equals one square foot of coverage at one inch of thickness.
How the math works: We multiply your area (sq ft) by your chosen thickness (inches) to get total board feet. Then we apply per-board-foot material costs and per-square-foot labor costs for your selected foam type, giving you low and high estimates.
Open-Cell vs Closed-Cell
Open-cell foam ($0.44–$0.65 per board foot) expands to fill cavities, offers excellent soundproofing, and has an R-value of R-3.7 per inch. It's lighter, more flexible, and ideal for interior walls and attics.
Closed-cell foam ($1.15–$1.75 per board foot) is denser, provides R-6.5 per inch, acts as a vapor and moisture barrier, and adds structural strength. It's preferred for basements, crawl spaces, and exterior walls.
R-Value and Thickness
R-value measures thermal resistance — higher is better. Closed-cell at 3 inches delivers R-19.5, meeting most wall code requirements. Open-cell at 5.5 inches provides R-20.4, filling a standard 2×6 wall cavity. Your climate zone (Zone 1–7) determines the minimum R-value your home needs.
Labor Factors
Labor costs ($0.50–$1.50 per sq ft) vary based on project accessibility, wall height, obstacles, and your metro area. Attics and open walls are cheaper to spray; enclosed cavities and high ceilings cost more. We recommend getting 2–3 local contractor quotes for the most accurate pricing.
Data Sources
Pricing data is compiled from HomeAdvisor, Angi, RSMeans, and verified contractor estimates across multiple US regions. We review and update this data regularly to reflect current material and labor rates.
Last updated: 2026-02-02
Frequently Asked Questions
How much does spray foam insulation cost per square foot? +
Spray foam insulation costs $1.75–$5.00 per square foot for closed-cell and $1.00–$3.50 per square foot for open-cell, including materials and labor. The exact cost depends on foam type, thickness, and your location.
Is closed-cell or open-cell spray foam better? +
Closed-cell foam has a higher R-value (R-6.5 per inch vs R-3.7), acts as a vapor barrier, and adds structural rigidity — but costs roughly twice as much. Open-cell is more affordable, provides good soundproofing, and works well for interior walls. Closed-cell is generally recommended for exterior walls, basements, and crawl spaces.
What is a board foot of spray foam? +
A board foot is the standard unit for measuring spray foam — it equals one square foot of coverage at one inch thick (12" × 12" × 1"). To calculate total board feet, multiply your area in square feet by the desired thickness in inches. For example, 500 sq ft at 3 inches thick = 1,500 board feet.
How thick should spray foam insulation be? +
For closed-cell foam, 2–3 inches is typical for walls (R-13 to R-19.5) and 3–5.5 inches for ceilings. For open-cell foam, 3.5 inches fills a 2×4 wall cavity and 5.5 inches fills a 2×6 cavity. Your climate zone and local building codes determine the minimum R-value required.
How long does spray foam insulation last? +
Spray foam insulation lasts 80–100 years when properly installed, making it one of the most durable insulation options. It does not sag, settle, or lose R-value over time like fiberglass batts can.
Can I install spray foam insulation myself? +
DIY spray foam kits are available for small projects (under 200 sq ft), costing $40–$80 per kit. However, large-scale installation is best left to licensed professionals who have the specialized equipment to ensure proper thickness, adhesion, and ventilation. Improper application can lead to off-gassing, poor coverage, and voided warranties.
Does spray foam insulation reduce energy bills? +
Yes. Spray foam creates an airtight seal that can reduce heating and cooling costs by 30–50% compared to uninsulated spaces. Most homeowners see a return on investment within 3–5 years through lower energy bills, especially in extreme climates.
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