Plasterboard Calculator - How Many Boards Do You Need? (UK)
Tell it the area you're boarding and the thickness you're using, and it works out how many sheets of plasterboard you need - with a sensible wastage allowance built in.
Interested? Then → Quotato for Plasterers · More advice on the Blog & Chips guides.
How to use this calculator
Measure the wall or ceiling you're covering and pop the total area in square metres into the box - for a wall that's length times height, for a ceiling it's length times width. Pick your board thickness (12.5mm is the everyday choice; 9.5mm is lighter and common on ceilings) and you'll get the number of sheets to buy.
How we calculate this
- We divide your area by the size of one board to get the raw number of sheets, then round up to whole boards.
- A standard UK plasterboard sheet is 2400×1200mm, which is 2.88 m² of coverage per board.
- We add 10% for wastage - cuts around windows, doors, sockets and offcuts you can't reuse.
Worked example
Boarding a wall 5m long and 2.4m high is 12 m². Divide 12 by 2.88 and you get 4.17 boards. Add 10% for wastage (4.58) and you're ordering 5 boards. For anything bigger the wastage really starts to matter.
UK notes & gotchas
- Standard UK plasterboard comes as 2400×1200mm sheets (8ft × 4ft) - that's the 2.88 m² figure we use.
- 12.5mm is the go-to for walls and most ceilings; 9.5mm is lighter for ceilings; moisture-resistant (green) and fire-rated (pink) boards cost more but board out the same.
- 12.5mm sheets are roughly 22kg each, so factor in a second pair of hands or a board lifter on ceilings.
FAQ
Does this include wastage?
Yes - we add 10% on top of the raw figure to cover cuts around openings, sockets and offcuts you can't reuse.
What size board does it assume?
A standard UK sheet of 2400×1200mm, which gives 2.88 m² of coverage per board.
Should I use 12.5mm or 9.5mm?
12.5mm is standard for walls and most ceilings and is more robust. 9.5mm is lighter and often used on ceilings - the board count is the same, the spec changes.
Do I need to take off doors and windows?
For a quick order it's fine to board the whole area and let the 10% wastage soak up the openings. On a wall with big patio doors, knock the opening areas off first.