Calculate exactly how much insulation you need for walls, ceilings, or floors. No waste, no guesswork.
Ready to calculate
Enter your area dimensions
R-3.2/inch
$0.64/sq ft
R-3.5/inch
$1.2/sq ft
R-6.5/inch
$2.5/sq ft
Why expert review matters
Every calculator is reviewed by certified professionals to ensure accuracy.David Chen's Master Mason, Licensed GC certification ensures professional-grade precision.
Hot climates
Attic: R-30
Wall: R-13
Mixed climates
Attic: R-38
Wall: R-13
Cold climates
Attic: R-49
Wall: R-20
Very cold
Attic: R-60
Wall: R-21
What R-value do I need?
Depends on climate zone (R-13 to R-60)
Can I add over existing?
Yes, if current insulation is dry
DIY or professional?
Batts DIY-friendly, spray foam needs pro
Our insulation calculator determines the amount of insulation material needed based on your project's dimensions and the desired R-value. The calculation accounts for coverage area, insulation thickness, and material density to give you accurate material estimates.
Formula
Target R-value ÷ R per inch = Thickness needed
Area ÷ Coverage per bag = Bags needed