Calculate the right amount of attic insulation for your climate zone. Get R-value recommendations, thickness, and cost estimates.
Ready to calculate
Enter your attic dimensions
R-30
Hot
R-38
Warm
R-49
Mixed
R-60
Cold
Why expert review matters
Every calculator is reviewed by certified professionals to ensure accuracy.David Chen's Master Mason, Licensed GC certification ensures professional-grade precision.
Can I add new insulation over old?
Yes, if existing insulation is dry and mold-free. Don't compress it.
What's the payback period?
Typically 2-5 years depending on energy costs and climate
Blown or batts for attic?
Blown is better for attics - fills gaps and easier to install over existing
Our attic insulation calculator determines how much additional insulation you need based on your climate zone's recommended R-value minus any existing insulation. It calculates the required thickness based on your chosen insulation type's R-value per inch, then estimates material quantities and costs.
Formula
Additional R-Value = Target R - Existing R
Thickness = Additional R ÷ R-Value per inch