Understanding the Insulation Calculator
An insulation calculator estimates how much insulation you need to reach a target R-value for walls, attics, or floors. Proper insulation cuts heating and cooling bills and keeps your home comfortable year-round.
Understanding R-value
R-value measures resistance to heat flow — the higher the number, the better the insulation. Recommended R-values vary by climate and by where in the home you are insulating, with attics typically needing the most. The calculator helps you find the material thickness or quantity required to hit the recommended level for your area.
Coverage and gaps
Different materials (batts, blown-in, foam) achieve a given R-value at different thicknesses and cover area differently, which the calculator accounts for. Just as important as quantity is installation: gaps, compression, and missed spots dramatically reduce real-world performance, so even coverage matters as much as the right amount.
Tips & things to know
- •Higher R-value means better insulation.
- •Attics generally need the most insulation.
- •Even coverage with no gaps is as important as the right amount.