Drywall Calculator
Estimate 4×8 or 4×12 drywall sheets for walls and ceilings. Includes waste for cuts around doors, windows, and corners.
Assumptions
- Standard 1/2 in gypsum board on walls; adjust sheet size to your selection.
- Default waste is 10% for simple rooms, 15% for many openings.
- Does not include moisture-resistant (green) board unless you order separately.
- Ceiling and wall areas are combined in one total area entry.
- No deduction for areas receiving other finishes unless you subtract them.
Sheets needed = ceil(wall/ceiling area with waste ÷ sheet area). Standard sheets: 4×8 = 32 ft², 4×12 = 48 ft².12 × 10 ft room, 8 ft walls, 4×8 sheets
- Wall area ≈ 352 ft² (same as paint calc). With 10% waste = 387 ft². 387 ÷ 32 = 12.1 → 13 sheets of 4×8.
How to measure
Calculate total square footage of surfaces to be drywalled. For rooms, sum all walls plus ceiling. Subtract large openings only if they occupy full floor-to-ceiling space.
Common mistakes
- Forgetting the ceiling when hanging a full room.
- Using 4×8 sheet count math on 4×12 sheets (48 ft² vs 32 ft²).
- Ordering too little for vaulted or angled ceilings with extra cuts.
Frequently asked questions
4×8 or 4×12 sheets?
4×12 reduces joints on long walls but is heavier and harder to handle alone. 4×8 is standard for DIY.
How much waste for many windows?
Bump waste to 12–15% when there are many cutouts and corners.
Does this include joint compound?
No. This is sheet count only. Compound and tape depend on joint linear feet.
Fire-rated or soundboard?
Sheet count is the same by area; order the correct board type for your code requirements.