How much R-21 insulation for 800 sq ft of garage?
Answer
17 batts (48 sq ft coverage each)
Total area: 800 sq ftR-value: R-21Coverage per batt: 48 sq ft
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How We Calculated This
Batts = ceil(Total Sq Ft / 48)
800 sq ft / 48 sq ft per batt = 17 batts
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Calculated using verified formulas. Last updated March 2026.