Insulation Calculator

Find the right thickness for your desired R-value.

Advertisement
Advertisement

How to Use the Insulation Calculator

  1. Enter the area you need to insulate in square feet.
  2. Enter your target R-value (check local building codes).
  3. Select the insulation type.
  4. Click Calculate to see the thickness needed and cost.

Formula

Thickness (inches) = Desired R-Value ÷ R-Value per Inch
Insulation Layer

Worked Example

To reach R-38 with standard fiberglass batts (R-3.2/inch), you'd need about 11.9 inches of insulation thickness.

About This Calculator

R-value requirements vary by climate zone and application (attic, wall, floor) — check your local building code for the recommended minimum before purchasing materials.

Frequently Asked Questions

How is insulation R-value need calculated?

It's based on climate zone, the area being insulated, and recommended R-value guidelines for that zone and application.

What does R-value mean?

It measures a material's resistance to heat flow — higher R-value means better insulating performance for a given thickness.

Why do R-value recommendations vary by region?

Colder climates need more insulation to prevent heat loss, while milder climates can use less and still maintain efficient homes.

Suggest a Calculator

👋 We noticed you might be using an ad blocker. This site is free thanks to ads — consider allowing them here to support us. Thanks!