Material calculator
Insulation Calculator
Calculate insulation packages for attics, walls, basements, or custom areas using coverage and waste.
These results are planning estimates only. Verify product labels, site conditions, local requirements, and professional guidance before buying or building.
Calculator inputs
Adjust the typical defaults below. Results update automatically.
Results
Review quantities, warnings, and the shopping list before buying.
Check these assumptions
- R-value target is a note only; verify climate zone and local requirements separately.
Project type
attic
Total insulation area
120sq ft
Area with waste
132sq ft
Packages to buy
3packages
Material list
- 3 packages Insulation packages48 sq ft coverage each
- 132 sq ft Coverage area with waste
- R-38 R-value target noteNot code advice
Breakdown
| item | length | width | unit | areaSqFt |
|---|---|---|---|---|
| Area 1 | 12 | 10 | ft | 120 |
How to use
- Choose a project type and enter one or more areas.
- Enter package coverage from the insulation label.
- Use the R-value field as a note and verify local requirements separately.
Input guide
- Package coverage is square feet per bag, roll, or package.
- R-value target is recorded as a note only.
- Price per package is optional and not live market data.
Common mistakes
- Using wall square footage when measuring attic floor area.
- Assuming this chooses a code-compliant R-value.
- Ignoring blocked bays, ventilation, moisture, or obstructions.
Assumptions and limitations
- No local R-value code judgment is included.
- No electrical, vapor barrier, ventilation, moisture, mold, or pest advice is included.
- Waste is a simple planning allowance.
Formula
- Total area = sum of each area length x width.
- Area to buy = total area x (1 + waste percent / 100).
- Packages needed = area to buy / package coverage, rounded up.
- Estimated cost = packages x optional user-entered price.
Example
A 600 sq ft attic with 10% waste and packages covering 48 sq ft needs 14 packages because 660 / 48 rounds up.
FAQ
Does this tell me what R-value I need?
No. It records your target as a note only. Verify climate zone and local requirements before buying.
Can this estimate rolls and bags?
Yes, as long as you enter the coverage per package from the label.