Drywall Calculator
Count the 4×8 drywall sheets a room needs for walls and ceiling.
Calculator
| 4×8 ft sheets for the ceiling (+10%) | 5 sheets |
|---|---|
| Wall area | 312 ft² |
How it is calculated
Walls = 2 × (12 + 12) × 8 = 384 sq ft minus openings = 312 sq ft. Each 4×8 sheet covers 32 sq ft; with 10% waste you need 11 sheets for walls and 5 for the ceiling.
About this calculator
A standard 4 × 8 foot sheet covers 32 square feet. The calculator finds the wall area from the room's size and ceiling height, subtracts typical door and window openings, adds 10% for waste and divides by 32. It does the same for the ceiling.
Longer 12-foot sheets reduce seams but are heavier to handle. Many walls use 1/2 inch board, while ceilings and some fire-rated assemblies use 5/8 inch; check local code and the framing spacing.
Worked examples
| Project | 4×8 ft sheets for walls (+10%) | Rough cost |
|---|---|---|
| a 12x12 ft room with 8 ft walls | 11 sheets | $132 – $242 |
| a 10x10 ft room with 8 ft walls | 10 sheets | $120 – $220 |
| a 14x16 ft room with 9 ft walls | 16 sheets | $192 – $352 |
| a 20x20 ft room with 10 ft walls | 24 sheets | $288 – $528 |
Buying notes
- Add joint compound, tape, screws and corner bead to your list.
- Hanging sheets horizontally on 8-foot walls reduces vertical seams.
- Use moisture-resistant board in bathrooms and other damp areas.
Quick answers by size
Click a size for the exact quantity and cost.
How to measure and use this calculator
- Measure the room's length, width and wall height.
- Enter the number of doors and windows.
- Read sheets for the walls and for the ceiling separately.
- Add joint compound, tape and screws to your shopping list.
Common mistakes
- Buying exact quantities with no waste allowance.
- Hanging sheets vertically on 8 ft walls, which creates more seams.
- Using standard board in wet areas.
Tips
- Hang sheets horizontally on 8 ft walls to reduce seams.
- Ceilings usually take 1/2 or 5/8 inch sheets; 5/8 resists sagging.
- Tape, mud and screws are extra: plan roughly one bucket of compound per 8–10 sheets.
Frequently asked questions
How many sheets of drywall for a 12x12 room?
About 11 sheets for the walls (with two doors and two windows) and 5 for the ceiling, including 10% waste.
What thickness of drywall should I use?
Half inch is common for walls. Five-eighths inch is often used for ceilings and fire-rated walls. Check local code.
How many sheets of drywall for a ceiling?
Divide the ceiling area by 32 and add about 10% for waste. The calculator shows this separately.