Attic blown-in insulation calculator
Bags of blown fiberglass or cellulose to bring an attic to the R-value you choose over what is there, with baffles and air sealing.
An estimate of the materials a job takes, worked out in your browser: check it against the job, and against your local code where it matters. Nothing you type leaves this page.
Put in the job's numbers and choices, and the list below follows them.
What it takes
Worked out for Attic floor 1,200 sq ft, Depth already there 3 in, Rafter bays at the eaves 30 each, R-value to reach: R-49, Insulation: Blown fiberglass.
Insulation
- Blown fiberglass insulation, bag 30 bag (Attic floor 1,200 sq ft × Depth to add 16.6 in) ÷ 700 (Blown fiberglass): 28.46 bag; plus 5% waste: 29.88; rounded up to whole bag: 30. Choose the R-value for your climate; check local code. Check the coverage chart on the bag you blow.
- Rafter vent baffle 30 each Rafter bays at the eaves 30 each: 30 each.
- Pro foam cans, 24 oz 4 can Attic floor 1,200 sq ft, one per 300: 4 can. Seal the top plates and penetrations first.
- Attic hatch insulation cover 1 each A fixed 1: 1 each.
- Attic insulation depth rulers 1 pack A fixed 1: 1 pack.
Labor
- Blown-in insulation 1,200 sq ft Attic floor 1,200 sq ft: 1,200 sq ft.
What it leaves out
- Removing old insulation
- Mold or pest remediation
- Bathroom fan venting
The same calculator in SMG Tools
In SMG Tools this calculator fills its numbers from the client's site measurements, prices every line from your own Price Book, checks the margin against your target, and carries the lines onto the proposal, the job's plan and the purchase order. It is one of the ready-made calculators SMG Tools sets up for gutters, siding and insulation, and calculators are on every plan.