Blown-In Insulation Volume & Bag Calculator

Volume = area × depth; bags come from the label coverage chart.

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Formula

Volume = area × depth ÷ 12
Bags = area ÷ coverage per bag at target R

Example calculation

1,200 ft² at 14 in → 1,400 ft³; at 40 ft²/bag → 30 bags.

Practical HVAC use

Attic retrofits.

Common mistakes

Using installed depth instead of the label's minimum settled thickness.

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Educational tool. Results are estimates from the stated formulas; always confirm with manufacturer data and the code adopted in your jurisdiction. All calculators