Spray Foam Calculator
Board Foot Calculator for Spray Foam
Calculate spray foam insulation coverage. One board foot equals 1 square foot at 1 inch thick.
Spray Foam Calculator
Calculate coverage for spray foam insulation kits
Note: Spray foam expands 30-100× its liquid volume. One board foot of cured foam covers 1 sq ft at 1" thick.
Closed Cell Foam
R-6 to R-7 per inch. Vapor barrier, structural strength. Best for exterior walls, roofs, and moisture-prone areas. More expensive.
Open Cell Foam
R-3.5 to R-4 per inch. Sound dampening, lower cost. Good for interior walls, attics (with vapor retarder), and soundproofing.
DIY Kits
Common sizes: 200 BF, 600 BF. At 2" thick, a 600 BF kit covers ~300 sq ft. Add 15-20% for waste and learning curve.
Frequently Asked Questions
How do I calculate spray foam board feet?
Board feet = Square feet × Thickness (inches). For a 100 sq ft wall at 2" thick: 100 × 2 = 200 board feet required.
What R-value do I need?
Depends on climate zone. Typical: R-13 to R-23 for walls (2-3" closed cell), R-38 to R-60 for attics (6-10" open cell).
How much waste should I plan for?
15-20% for experienced users, 25-30% for DIY beginners. More waste in complex areas with many corners and penetrations.