Calculate how many sheets of drywall (plasterboard in the UK) you need to board a room. Choose your sheet size, include the ceiling if you are boarding it, and get screws and tape on the shopping list.
Your shopping list
How to measure
- Measure the length of each wall and the height of the room.
- Estimate the total area of doors and windows.
- Decide if you are boarding the ceiling too.
The formula
Area = 2 × (length + width) × height − openings (+ ceiling) Sheets = area × (1 + waste %) ÷ sheet area (round up)
Worked example
A 12 × 12 ft room with 8 ft walls: 384 sq ft of wall − 36 sq ft of openings + 144 sq ft of ceiling = 492 sq ft. With 10% waste and 4 × 8 sheets: 492 × 1.1 ÷ 32 = 16.9, so 17 sheets.
Tips before you buy
- Longer sheets mean fewer joints to tape and fill, which saves time.
- Use moisture-resistant board in bathrooms and kitchens.
- Screws should sit just below the paper surface without tearing it.
Frequently asked questions
What is the difference between drywall and plasterboard?
They are the same product. Drywall is the US and Canadian term, plasterboard the UK and Australian term.
How many screws per sheet of drywall?
About 32 for a 4 × 8 ft sheet on walls, a few more on ceilings.
Which way should drywall be hung?
Horizontally on walls in most homes, as it gives fewer joints. Ceilings are boarded first, then walls.
Results are estimates for planning only. Always check quantities with your supplier before you buy.