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Insulation Calculator

Use measured wall, attic, floor, or crawlspace area and the product label's coverage to estimate full packages, waste, labor, and project cost.

22-calculator project library Reviewed 2026-07-25Calculations run privately in your browser

Enter project details

Example values are prefilled
Coverage
sq ft
%
sq ft

Use the coverage at your required R-value.

Cost
$
$
$
Location and tax assumptions

The location factor adjusts labor only. Replace all default prices with actual local quotes before purchasing.

A coarse planning adjustment—not a ZIP-code quote.

%

Enter the tax rate that applies to taxable materials.

All default prices are editable examples. Cost scenarios vary the entered plan; they do not represent bids or guarantees.

How to use this insulation calculator

Estimate insulation bags or bundles, coverage, waste, material cost, labor, and project totals.

Formula

Order area = measured area × (1 + waste %). Packages = order area ÷ labeled coverage at the target R-value, rounded up.

Worked example

Example: For 1,000 sq ft with 8% waste and 40 sq ft per package, order area is 1,080 sq ft and the estimate is 27 packages.

Accuracy and limitations

Coverage can change by R-value, cavity size, installed thickness, settling, and framing. Always use the exact product chart and local code requirements.

Frequently asked questions

Why use coverage at the target R-value?

Blown and batt products can cover different areas depending on installed thickness and thermal target.

Should framing area be deducted?

Product coverage labels and common takeoffs generally work from gross cavity area; follow the manufacturer's method.

Does this determine the required R-value?

No. Required R-values vary by climate zone, assembly, and local energy code.

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