Home & Renovation
Drywall Calculator
Calculate sheets of drywall needed for a renovation project.
Drywall (gypsum board) sheets are standard 4×8 (32 sq ft) or 4×12 (48 sq ft). This calculator determines sheet count for walls and ceiling in a room, accounting for door and window openings.
Drywall Sheets Needed
14 sheets
- wall Area
- 381 sq ft (walls)
- total Area
- 381 sq ft total
- without Waste
- 12 sheets (no waste)
- note
- 4×8 sheets at 32 sq ft each
Formula and method
Sheets = ⌈Net Area / 32⌉ × 1.10 waste
Standard 4×8 drywall = 32 sq ft. Door opening deduction: 21 sq ft (3×7). Window deduction: 15 sq ft (average). 10% waste added for cuts.
Worked examples
Standard bedroom
- Room Perimeter (ft):
- 48
- Wall Height (ft):
- 9
- Number of Doors:
- 1
- Number of Windows:
- 2
- Include Ceiling?:
- No
- Floor Area for Ceiling (sq ft):
- 144
Drywall Sheets Needed: 14 sheets
Full room with ceiling
- Room Perimeter (ft):
- 52
- Wall Height (ft):
- 9
- Number of Doors:
- 2
- Number of Windows:
- 3
- Include Ceiling?:
- Yes
- Floor Area for Ceiling (sq ft):
- 180
Drywall Sheets Needed: 20 sheets
Assumptions and limits
- 4×8 ft (32 sq ft) drywall sheets
- Average door = 3×7 ft, average window = 3×5 ft
This tool provides an educational estimate. Rules, rates and personal circumstances can change the answer. Review the assumptions before relying on a result. Report a correction.
Common mistakes to avoid
- Not adding waste — cuts always result in partial sheets being discarded.
- Forgetting corners require extra — inside and outside corners affect board placement.
- Using 48 sq ft (4×12 sheets) formula when ordering standard 4×8.
Frequently asked questions
Should I use 4×8 or 4×12 drywall?
4×8 is standard and easier to handle alone. 4×12 sheets reduce seams on taller walls (10-12 ft ceilings) but require two people. For a 9-ft ceiling, 4×8 with horizontal installation leaves a 1-ft strip at the bottom.
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