Drywall Calculator
Work out how many sheets of drywall, plus screws, mud and tape, you need to finish a room.
How to use this drywall calculator
Enter the room's length, width and wall height, and count the doors and windows. The calculator takes off about 21 sq ft per door and 15 sq ft per window. Choose your sheet size and whether you're also hanging the ceiling. You'll get the number of sheets with 10% extra for cuts, plus rough amounts of screws, joint compound and tape.
Which sheet size should I use?
- 4 × 8: the easiest to carry and fit up stairs. A good choice when working alone.
- 4 × 12: fewer seams, so less taping and a smoother finish. But they're heavy and usually need two people.
- Thickness: ½ inch is standard for walls. Use ⅝-inch fire-rated (Type X) where code requires it, such as walls shared with a garage.
- Wet areas: use moisture-resistant board in bathrooms, and cement board behind tile in showers.
The math behind it
Wall area = 2 × (length + width) × height, minus doors and windows. Add length × width if you're hanging the ceiling. Sheets = total area × 1.1 ÷ sheet area, rounded up. Rough rules of thumb for the rest:
| Material | Rule of thumb |
|---|---|
| Screws | About 32 per 4×8 sheet (≈1 per sq ft) |
| Joint compound | About one 4.5-gal bucket per 480 sq ft |
| Paper tape | About 370 ft per 1,000 sq ft |
Example: a 12 × 10 ft room with 8-foot walls, one door and one window has 316 sq ft of wall. Adding the 120 sq ft ceiling makes 436 sq ft. With 10% extra, that's 15 sheets of 4×8 drywall.
Often used together
Quick answers
How many sheets of drywall do I need for a 12 × 12 room?
With 8-foot walls, one door, one window and the ceiling, about 17 sheets of 4×8, including 10% extra for cuts.
How many screws per sheet of drywall?
About 32 screws per 4×8 sheet on walls, with framing 16 inches apart. Ceilings often get a few more.
Should I use 4×8 or 4×12 sheets?
4×12 sheets mean fewer seams to tape, but they're heavy and awkward. 4×8 sheets are easier to handle alone and fit through doors and up stairs.