Insulation Calculator

R-value measures thermal resistance - how well insulation resists heat flow. Higher R-values mean better insulating performance. The right R-value depends on your climate zone and the area being insulated (attic, walls, basement).

Attic insulation thickness varies by R-value target and material type. For R-30, you typically need 8-10 inches of blown-in fiberglass, 10-14 inches of cellulose, or 6-8 inches of fiberglass batts.

Yes, you can usually add new insulation over existing insulation to increase the total R-value. Make sure the existing insulation is dry and in good condition. The new insulation should be unfaced to prevent vapor barrier issues.

Batt insulation comes in pre-cut panels that fit between studs, while blown-in insulation is loose material installed with special equipment. Blown-in provides better coverage around obstacles and irregular spaces.

Coverage varies by insulation type and target R-value. A typical bag of blown-in fiberglass covers 40-60 square feet at R-30, while cellulose covers 25-40 square feet. Check manufacturer specifications for exact coverage.

Yes, different areas require different R-values. Attics typically need R-30 to R-60, exterior walls need R-13 to R-21, and basements need R-10 to R-15, depending on your climate zone.

Batt insulation in accessible areas can be DIY-friendly. However, blown-in insulation requires special equipment and expertise. Consider professional installation for spray foam, dense-pack applications, or hard-to-reach areas.

Proper insulation can reduce heating and cooling costs by 15-50% depending on your current insulation levels and climate. The investment typically pays for itself within 2-10 years through energy savings.