Do you have a contractor’s quote for an insulation upgrade? Use our calculator, which is based on an equation from the U.S. Department of Energy, to find out how long it will take for your energy savings to pay back your investment.

WHAT YOU NEED TO USE THIS CALCULATOR:
1. Determine what type of insulation, and what thickness of insulation, you now have in your walls or attic.
2. Estimate the square footage of the walls or attic space to be upgraded.
3. Find a recent copy of your utility or fuel bill to determine the cost per unit of your space heating fuel.
4. Finally, have a copy of the quote from your contractor, or—if you plan to do the work yourself—the cost of the necessary insulation materials and installation equipment.

ABOUT THIS CALCULATOR:
The equation that powers this calculator was developed by the U.S. Department of Energy. In addition to the details you enter, it relies on government-compiled information, including the average number of heating days per year in your region, the average efficiency of various heating systems, and the average performance of the insulation products available to builders and homeowners. All of these factors help provide a more accurate calculation, no matter where you live or what type of fuel you use to heat your home.

That said, this calculator is not perfect. For example, it does take into account fluctuations in energy costs. And it doesn't account for other factors specific to your home, like air leakage. For a more complete overview of things to consider when planning an energy upgrade, read Mike Guertin's A Complete Guide to Estimating Energy Efficiency Payback.