R-60 thickness by insulation type
| Material | Typical R per inch | Thickness for R-60 |
|---|---|---|
| Blown fiberglass | R-2.5 | 24 in |
| Blown cellulose | R-3.5 | 17.1 in |
| Fiberglass batts | R-3.2 | 18.8 in |
| Mineral wool batts | R-3.3 | 18.2 in |
| Open-cell spray foam | R-3.6 | 16.7 in |
| Closed-cell spray foam | R-6.5 | 9.2 in |
R-60 is an attic level recommended by ENERGY STAR for colder climates (and for warm zones when starting from scratch). These depths use typical R-per-inch values; the label or bag chart for your product gives the exact settled thickness.
How much material for 1,000 sq ft at R-60?
Blown fiberglass at 24 inches over 1,000 sq ft is about 2,000 cubic feet of installed insulation; cellulose at 17.1 inches is about 1,429 cubic feet. Bag coverage varies by product, so enter the coverage from the bag chart in the calculator above to get an exact bag count.
The math
Common questions
How thick is R-60 blown-in insulation?
About 24 inches of blown fiberglass or 17.1 inches of blown cellulose.
How thick is R-60 batt insulation?
About 18.8 inches for standard fiberglass batts (R-3.2 per inch); high-density batts are thinner.
Want the full method, tips and other sizes? See the insulation calculator guide.