Blown-in cellulose: R-value per inch
Short answer
Blown-in cellulose adds about R-3.5 per inch, so you need roughly 8.6" for R-30 and 14.0" for R-49.
R-value per inch
R-3.5
Best for
Attics and dense-packed walls
Blown-in cellulose thickness chart
| Target R-value | Thickness needed |
|---|---|
| R-13 | 3.7" |
| R-19 | 5.4" |
| R-30 | 8.6" |
| R-38 | 10.9" |
| R-49 | 14.0" |
| R-60 | 17.1" |
How much for your home?
Calculate blown-in celluloseOther materials
Frequently asked questions
How many inches of blown-in cellulose do I need for R-49?
About 14.0" of blown-in cellulose, since it adds roughly R-3.5 per inch (R-49 ÷ 3.5).
What is the R-value of blown-in cellulose per inch?
Blown-in cellulose provides about R-3.5 per inch (a typical value — density and brand vary). So 8.6" gives roughly R-30.
What is blown-in cellulose best used for?
Attics and dense-packed walls. Compare it against other materials for your target R-value in the calculator.