Calculate insulation quantity, R-value and cost. Shows a potential credit only when selected; verify current eligibility.
Formula: Determine target R-value by climate zone and location. Calculate area. Divide by coverage per bag/roll at target R-value (check product label).
| Climate Zone | Attic | Wall (2×4) | Wall (2×6) | Floor |
|---|---|---|---|---|
| 1-2 (FL, TX, AZ) | R-30 | R-13 | R-21 | R-13 |
| 3-4 (CA, GA, TN) | R-38 | R-13 | R-21 | R-19 |
| 5-6 (NY, IL, WA) | R-49 | R-13 | R-21 | R-25 |
| 7-8 (MN, AK, ND) | R-60 | R-13 | R-21 | R-30 |
| Type | R/inch | $/sq ft (installed) | Best For |
|---|---|---|---|
| Fiberglass batt | R-3.2 | $0.80-1.50 | Walls, DIY |
| Blown fiberglass | R-2.5 | $1.00-2.00 | Attics |
| Cellulose | R-3.7 | $1.20-2.50 | Attics, dense walls |
| Spray foam | R-5-6 | $1.50-3.50 | Air sealing, premium |