Drywall Calculator
Calculate how many sheets of drywall you need for a room, accounting for doors and windows.
Drywall Sheets Needed
Drywall sheets are calculated from the total wall area minus openings, divided by the sheet size.
Wall Area = Perimeter × Height
Net Area = Wall Area − (Doors × 21 sq ft) − (Windows × 15 sq ft)
Sheets = Net Area / Sheet Size
Standard sheet sizes:
- 4 × 8 ft = 32 sq ft (1.22 × 2.44 m = 2.97 m²)
- 4 × 12 ft = 48 sq ft (1.22 × 3.66 m = 4.46 m²)
Imperial: Room dimensions in feet. Standard door ~21 sq ft, standard window ~15 sq ft. Metric: Room dimensions in meters. Standard door ~1.95 m², standard window ~1.39 m².
Always add 10–15% extra for waste and cuts.