Roof Insulation Calculator
Calculate proper insulation R-value and material needed
How to use this calculator
The Master Roofer here—follow these steps to get a solid estimate:
- Enter your attic floor area in square feet.
- Select your climate zone (1–8) for recommended R-value.
- Optionally enter current R-value to see how much to add.
- Click Calculate to see recommended R, bags needed, and estimated cost.
Higher R-value = better insulation. Utah is typically Zone 4–5.
R-Value: Measures insulation's resistance to heat flow. Higher R-value = better insulation.
Climate Zones: Based on U.S. Department of Energy recommendations