Plasterboard
Plasterboard sheets for an area
- where
- area of one sheet (m²)
- board length (m)
- board width (m)
- sheets needed, unrounded
- area to board (m²)
- waste allowance (%)
- whole sheets to buy
Explain this equation
This gives the number of plasterboard sheets to cover a wall or ceiling area, with an allowance for cutting.
Sa is the face area of one board, length L times width B. A is the area to cover and w the cutting waste. N is the exact number of boards, which is rounded up.
The calculation is plain area division: total area including waste divided by the area of one board. Boards come whole, so the answer is rounded up.
Sense check: a standard 2400 × 1200 board is 2.88 m², so a 30 m² room with 10% waste needs about 11.5 boards, which means 12.
Watch out: rooms with many openings, or walls just taller than the board length, waste more than 10%. Lay out awkward walls board by board.
Number of plasterboard sheets for a wall or ceiling area, with a cutting allowance.
Enter your values to see the result.
Good to know
Common UK sizes: 2400 × 1200 mm (2.88 m²), 2700 × 1200, 3000 × 1200 and 1800 × 900 mm (handy for one-person ceilings). Allow about 10% for cutting on plain rooms and more for many openings, splays or short offcuts that cannot be reused. Choose a board length that matches the wall height to avoid end joints.
Common mistake
Ordering by area alone in a room with lots of openings or a height just over a board length, where every sheet leaves an unusable offcut.
Limits
Area-based estimate. For accuracy on a small or awkward job, set out the board layout per wall.
Sources
Results are calculations from the published methods and manufacturer figures shown, and depend on the data you enter. Always follow the manufacturers’ system and product data, BS 8212, BS EN 13914 and Building Regulations. Coverage rates vary by product, background and thickness. Check prices, VAT and CIS rules with your own records and HMRC.