How much R-21 insulation for 3,000 sq ft of garage?
Answer
63 batts (48 sq ft coverage each)
Total area: 3,000 sq ftR-value: R-21Coverage per batt: 48 sq ft
Need a custom calculation?
Open the full calculator with custom inputs
How We Calculated This
Batts = ceil(Total Sq Ft / 48)
3,000 sq ft / 48 sq ft per batt = 63 batts
Related Calculations
How much R-30 insulation for 800 sq ft of attic?17 batts (48 sq ft coverage each)How much R-38 insulation for 800 sq ft of attic?17 batts (48 sq ft coverage each)How much R-49 insulation for 800 sq ft of attic?17 batts (48 sq ft coverage each)How much R-13 insulation for 800 sq ft of walls?17 batts (48 sq ft coverage each)How much R-19 insulation for 800 sq ft of walls?17 batts (48 sq ft coverage each)
Calculated using verified formulas. Last updated March 2026.