Insulation Calculator
Estimate bags, rolls or bundles of insulation using the package coverage printed by the manufacturer. Add cutting waste and optional package price.
How this calculator works
Project area is increased by the waste allowance, divided by one package’s stated coverage, and rounded up so the order covers the whole surface.
Formula: packages = ceil(area × (1 + waste) ÷ package coverage)
Worked example
A 1,000 ft² project with 10% waste needs 1,100 ft² of coverage. If each package covers 40 ft², round 27.5 up to 28 packages.
Before you order
- Choose R-value and insulation type from local energy code, not area alone.
- Use the exact package coverage for your framing spacing and product thickness.
- Subtract only large openings; small cavities often offset cuts and fitting waste.