Insulation Coverage Calculator

Estimate insulation square footage and package count from an area, waste allowance, and the coverage printed on each roll or batt package.

Area length (ft)Area width / height (ft)Waste (%)Coverage per package (sq ft)

Ready.
Enter your measurements and calculate.

Worked example

Example

A 30 × 20 ft area is 600 sq ft. At 5% extra and 70 sq ft per package, buy nine packages.

References

Last reviewed September 1, 2026. Defaults are starting points; product-specific inputs are editable wherever coverage varies.

Next calculation

FAQ

No.

Yes for quantity when you know the measured area and package coverage.

For simple purchasing estimates many people use gross cavity area; detailed takeoff can account for framing and openings.