Insulation Calculator
Work out how much insulation to buy: required thickness for a target R-value from the product’s R-per-inch, and package count from printed coverage. Suitable for batts, rolls and rigid board.
Insulation Calculator
Energy & Efficiency
ft²
Check local code: common wall targets R-13 to R-21 (climate dependent).
ft²
%
Packages to buy
6packages
528 ft² incl. waste
Required thickness
4.06in
10.3 cm at R-3.2/in
R-value per inch
3.2
verify on product datasheet
Calculation breakdown
- 1Thickness:
R-13 ÷ 3.2 = 4.06 in - 2Packages:
⌈528 ÷ 88⌉ = 6
- Faced batts: vapor retarder orientation depends on climate — see local code guidance.
Thickness = Target R-value ÷ R-value per inch.
Packages = ⌈Area × (1 + Waste) ÷ Package coverage⌉.