BuildCalcs Plasterboard Calculator
Enter your wall dimensions and plasterboard sheet size to estimate how many boards to buy.
How the plasterboard calculator works
The calculator first works out the wall area, then divides it by the area of one plasterboard sheet. Your selected waste allowance is added before the result is rounded up to the next whole board.
Plasterboard quantity formula
Boards required = wall area ÷ board area, plus allowance, rounded up
Worked example: 4.8 m × 2.4 m wall
A 4.8 m wide by 2.4 m high wall has an area of 11.52 m². A standard 2400 × 1200 mm board covers 2.88 m², so exactly four boards cover the theoretical area. With a 10% allowance, the calculator rounds the requirement up to 5 boards.
Single-sided and double-sided stud walls
If a stud partition is being boarded on both faces, both sides need to be included. For two identical faces you can calculate one side and double the quantity, or calculate each face separately where openings or dimensions differ.
Typical UK plasterboard sheet sizes
Common board dimensions include 2400 × 1200 mm, 2700 × 1200 mm and 3000 × 1200 mm, with some products also supplied at 900 mm wide. Sheet thickness, board type and edge profile do not change the area calculation, but they do matter when choosing the correct product.
Doors, windows and awkward layouts
The calculator uses one rectangular wall area and does not automatically deduct openings. For a precise quantity on a wall with large doors or windows, calculate the remaining rectangular sections separately. On smaller openings, offcuts and cutting waste can sometimes offset much of the apparent saving.
Frequently asked questions
How much plasterboard waste should I allow?
10% is a useful planning starting point for a simple rectangular wall. Rooms with many cuts, corners, openings or damaged sheets may need a larger allowance.
Does this calculator include ceilings?
No. Calculate the ceiling separately using its plan dimensions, then add that board quantity to the wall requirement.
Does plasterboard thickness change how many sheets I need?
No. Thickness changes the product specification but not the surface area covered by a sheet of the same width and length.
Should I round up the number of boards?
Yes. Plasterboard is purchased as whole sheets, so the calculator always rounds the final requirement upward.