Insulation Calculator
How many batt packs of insulation you need
Insulating walls or a ceiling? Enter the area to estimate how many packs of batt insulation to buy.
How much insulation?
Batt insulation is sold by the pack, each covering a stated square footage — commonly around 40 ft². Match the batt width to your stud or joist spacing (16" or 24" on center) and check the R-value for your climate.
Frequently asked questions
How do I know how much insulation to buy?
Calculate the wall/ceiling area, then divide by the coverage printed on each pack (often ~40 ft²).
What R-value do I need?
It depends on your climate zone and where you're insulating — check local code or the DOE recommendations.