House Insulation Calculator

A House Insulation Calculator helps you figure out exactly how much insulation you need—down to the R-value and material quantities—so you can order the correct number of batts or rolls and avoid costly over- or under-buying. It tailors its recommendation to your local climate zone, the part of the house you’re insulating, and your project’s square footage. You can also use our window to wall ratio calculator to evaluate how your window area affects heat loss and overall insulation performance.

How to use it

1. Enter your county & state
   Start typing your county (e.g. “Jefferson, CO”), pick the match, and click Next. The calculator will look up your climate zone automatically.
2. Choose your project type
   Click “Attic,” “Basement,” “Wall,” etc., and answer any follow-up questions (e.g. “Above or below grade?”). As soon as all selections are made you’ll see your recommended R-value right on step 1.
3. Confirm R-value & enter area
   Click Next, then enter the total square footage to insulate. Click Next again.
4. Review material estimate
   You’ll get your climate-adjusted R-value, total area, and the exact number of insulation packs (with coverage) you need.
5. Start over
   Click Start over at any time to reset and begin again.

Key benefits

• Climate-specific recommendations—no manual lookup required.
• Inline R-value preview as you make selections.
• Exact material quantities so you avoid waste.
• Step-by-step wizard keeps it simple.
• No surprises—order exactly what you need before you get to the job site.

• For complete energy efficiency planning, use our air exchange rate calculator to measure how air movement impacts your insulation effectiveness.