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Insulation Calculator

Estimate insulation area, packs and project quantities.

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Calculator inputs

Insulation project details

Ready to calculate

Area to insulate

Choose the surface you are insulating. PlanCalq estimates quantity only—it does not choose the required R-value for your climate or building code.

Doors & windows

For walls, openings can be deducted from the insulation area.

Insulation product

Use the square-area coverage printed on one package. Choose the correct R-value and product width separately using local code and manufacturer guidance.

Optional cost estimate

Add a package price to estimate the insulation purchase cost.

Quantity estimate only. Verify required R-value, vapor-control strategy and installation details locally.
Your estimate

Ready when you are

Estimate insulation coverage, waste, packages to buy and optional material cost.

Plan with confidence

How to use the Insulation Calculator

Estimate how many insulation packages are needed to cover walls or a ceiling using the coverage printed on the product package.

Step by step

What to enter

  1. Choose a room, single wall or ceiling and enter the dimensions.
  2. Deduct doors and windows where applicable.
  3. Enter the coverage supplied by one insulation package.
  4. Choose waste and optionally enter the package price.
Method

How the calculation works

PlanCalq calculates the net surface area, adds your selected waste allowance and divides the result by the coverage of one insulation package.

The quantity is rounded up to full packages. Any R-value field is informational only; PlanCalq does not decide the insulation performance required for your building.

Calculation summaryGross area − openings = net insulation areaNet area × (1 + waste %) = recommended coverageRecommended coverage ÷ package coverage = packages to buy (rounded up)
Common questions

Insulation Calculator FAQs

Does PlanCalq tell me what R-value I need?

No. The correct R-value depends on location, building assembly and applicable standards or codes.

Should I subtract windows and doors?

Yes when estimating wall insulation, especially where openings represent a meaningful share of the wall area.

Why use package coverage instead of batt dimensions?

Package coverage is the simplest product-specific input and already accounts for how much material is contained in the package you will actually purchase.