Rigid Foam Board Calculator
Rigid foam sheets are often sold in 4×8 panels like drywall. Enter insulated area for sheet count.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
Step 3
How to use this calculator
Net area of continuous insulation layer. Add waste for window wraps.
What the math is doing
Sheets = area ÷ 32 sq ft per sheet × (1+waste), rounded up.
Frequently asked questions
Taped seams?
Add tape linear feet separately.
Multiple layers?
Multiply sheet count by layers.
Termite shields?
Follow local code for exposed foam on foundations.
Thickness codes?
Verify required R-value for your zone.