Insulation R-Value Calculator
Add layers; the total R-value is their sum. Target R-30+ for attic in cold climates, R-13 to R-21 for walls.
| Material | Thickness (in) | R-value |
|---|
- Total R-value
- —
- Climate zone target
- Wall: R-13 to R-21 · Attic: R-30 to R-60
About this tool
Insulation R-Value Calculator is a single-purpose utility on instant.tw, a free toolbox of calculators, converters, generators, and quick lookups. Everything works in your browser — nothing is uploaded, nothing is stored on a server unless explicitly noted.
Category: Trade & Construction Calculators. Browse more Trade & Construction Calculators tools.