Calculated result
32bags
Blown-in bags to order
Formula
EXT-BLOWN-0011200 ft²
Net coverage area
1260 ft²
Area including waste
25 bags / 1,000 ft²
Chart rate
Exterior calculator
Blown-in insulation calculator
Blown-in bag count from coverage area and the selected product's bags-per-thousand-square-feet chart value.
Reviewed formula · v1.0.0
Project inputs
Enter field measurements. Unit conversion happens before the reviewed formula is applied.
All values can be refined when you edit the estimate. This tool does not replace field verification or local requirements.
Transparent cost view
Use visible planning values, then replace them with actual job costs before quoting.
Material cost$2,720
Direct cost$3,110
Overhead + contingency$311
Markup + tax$411
Estimated project total$3,832
How this calculator works
A transparent blown-in insulation calculator takeoff.
This calculator multiplies attic or floor area by the selected product's bags-per-1,000-square-feet chart value, then applies a visible settling allowance before whole-bag rounding.
Worked example. Example: a 40 ft × 30 ft attic is 1,200 ft². At 25 bags per 1,000 ft² with 5% allowance, the order rounds to 32 bags.
- 1. Measure the actual coverage area, not the building footprint if eaves are blocked.
- 2. Copy bags-per-1,000-ft² from the selected cellulose or fiberglass chart at the planned settled depth or R-value.
- 3. Confirm baffles, existing insulation and ventilation independently.
Need the broader workflow? Read the exterior planning guide.
Questions
Common questions about this blown-in insulation calculator.
Does this choose an R-value?
No. The chart value you enter already corresponds to a product depth or R-value. This tool does not convert climate codes into bags.
Can I use this for batts?
No. Use the batt/roll insulation calculator for packaged batts. Blown-in coverage is a different chart.