Attic Insulation Calculator
Plan attic insulation quantity for thermal upgrades based on attic footprint and depth.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
Step 3
How to use this calculator
Enter attic area and desired insulation depth.
What the math is doing
Volume = area × depth. Bags ≈ cu ft ÷ 33 per bag.
Frequently asked questions
Settled depth?
Use manufacturer settled thickness, not blower hose peak.
Baffles at eaves?
Maintain vent channel before adding depth.
Recessed lights?
Use rated covers before burying with insulation.
Air sealing first?
Yes; air leaks undermine R-value gains.