Free tool · boards
How many plasterboards?
I count the sheets off the area, then look at the cuts, before I load the van.
This page works out 2,400 × 1,200 mm boards, or 2,400 × 900 mm boards, from an area you already measured. If you add the length and the height, it also estimates screws and joint tape. The skim for those boards is the plaster calculator. The figures stay in the browser.
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How the sheets are worked out
A 2,400 × 1,200 mm sheet is 2.88 m². A 2,400 × 900 mm sheet is 2.16 m². Those are the nominal sizes on the Gyproc WallBoard 12.5 mm (opens in a new tab) page, multiplied out. The page also lists longer sheets. This calculator does not. The area, after openings, is divided by the sheet, increased by the wastage you type, and rounded up.
Screws need the length and the height. Supports are assumed to run up the height, at the spacing you type, with a support at each end. Screws sit along each support at the field spacing, including both ends. British Gypsum's fixing clauses (opens in a new tab) say partitions and linings are fixed at maximum 300 mm centres, and ceilings at maximum 230 mm centres. The same clauses tighten that to 200 mm at external angles, and to 150 mm at ceiling board ends and perimeters. This count uses the field spacing only, so it can be light on a ceiling or on a run of external corners. Read on 18 October 2026.
Tape is the joints between boards on that rectangle. It is not the perimeter, a corner of the room, or the lining around an opening. Gyproc Joint Tape (opens in a new tab) is a 150 m roll. The 600 mm support spacing is a starting figure you can change. It is not a spacing the fixing clause sets. If an offcut will not cover the next cut, order the higher of the two sheet counts. Other free tools are on the tools page.
Common questions
Which board sizes does this use?
2400 by 1200 mm, and 2400 by 900 mm. Both are on the Gyproc WallBoard 12.5 mm product page, read on 18 October 2026. A 2400 by 1200 sheet is 2.88 square metres. A 2400 by 900 sheet is 2.16 square metres. That is the nominal size multiplied out. Longer sheets are sold, and they are not on this page.
Where does the screw spacing come from?
British Gypsum's plasterboard fixing clauses. Partitions and linings are fixed at maximum 300 mm centres. Ceilings are fixed at maximum 230 mm centres. The same clauses use 200 mm at external angles, and 150 mm at ceiling board ends and perimeters. This count uses the field spacing only, so a ceiling or a run of external corners can need more screws.
What is the tape figure?
The joints between boards on the rectangle you typed. It is not the perimeter, a corner of the room, or the lining around a door. Gyproc Joint Tape is a 150 m roll on the data sheet. One short joint still means buying a roll.
Why are there two sheet counts?
One is the area, plus the wastage you typed, rounded up. The other is how many sheets cover the length and height if an offcut is not reused on the next cut. If the cuts will not fit, order the higher number.