Plasterboard Sizes and Coverage (UK)

The short answer: divide the wall area by the sheet's m², then round up

In the UK the material is called plasterboard (not drywall). The standard sheet is 2400 × 1200 mm, which covers 2.88 m². A smaller 1800 × 900 mm sheet, covering 1.62 m², is easier to handle in tight spaces. To work out how many sheets you need, add up the wall or ceiling area, divide by the coverage of the sheet you are using, and round up to whole sheets.

Plasterboard comes in two common thicknesses — 9.5 mm and 12.5 mm — and two edge types. Tapered-edge board has a shallow recess along the long edges so joints can be taped and filled for a flat painted finish; square-edge board is used where the whole surface will be skimmed with plaster. British Gypsum Gyproc WallBoard is supplied in both thicknesses and both edge types to EN 520 Type A.

Sheet sizes, coverage and sheets per example wall

Coverage is simply the sheet's length multiplied by its width: 2400 × 1200 mm = 2.4 × 1.2 = 2.88 m², and 1800 × 900 mm = 1.8 × 0.9 = 1.62 m². Divide the area to be boarded by the sheet coverage and round up, because part sheets rarely tile perfectly onto a wall.

The larger 2400 × 1200 mm sheet covers a wall in fewer boards and fewer joints; the 1800 × 900 mm sheet is lighter to lift and fit single-handed. 1200 mm wide boards also come in longer lengths (such as 2700 and 3000 mm) if they suit the wall height better.

Worked example: a stud partition 3.0 m long and 2.4 m high

A stud partition is boarded on both faces. Each face is 3.0 × 2.4 = 7.2 m², so the two faces total 7.2 × 2 = 14.4 m². Using 2400 × 1200 mm sheets at 2.88 m² each: 14.4 ÷ 2.88 = 5.0, so five sheets exactly by area.

Check it by layout too: standing a 2400 mm board upright covers the full 2.4 m height, and 3.0 m of width ÷ 1.2 m per board = 2.5 boards, rounded up to 3 boards per face, which is 6 boards for both faces. Take the higher of the two methods and add roughly 10% for cuts: order 6 sheets. Choose tapered edge if you will tape and joint, or square edge if the wall will be skimmed.

Before you buy: plasterboard checklist

Confirm these before ordering so the boards suit the wall and the finish.

• Wall or ceiling area measured in metres and totalled (both faces for a partition).
• Sheet size chosen (2400 × 1200 mm standard, or 1800 × 900 mm for tight access).
• Thickness chosen (9.5 mm or 12.5 mm) to suit the framing and specification.
• Edge type chosen: tapered for taping and jointing, square for skimming.
• Area divided by sheet coverage and rounded up to whole sheets.
• About 10% added for cuts and offcuts.

Common mistakes ordering plasterboard

These are the errors that lead to extra trips to the merchant or the wrong finish.

• Boarding a partition on one side only in the estimate, then finding you need twice the sheets.
• Buying square-edge board when the plan is to tape and joint (that needs tapered edge), or tapered board when the wall will be fully skimmed.
• Ordering the exact area with no waste allowance for cuts around openings and services.
• Mixing up 9.5 mm and 12.5 mm board so thicknesses do not match across the room.
• Choosing the large 2400 × 1200 mm sheet where access or lifting makes the 1800 × 900 mm sheet more practical.

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Related measurement guides

• How much paint do I need? (UK) →
• Ballast and cement for concrete (UK) →

Sources and limits

Check the project-specific details

• British Gypsum Gyproc WallBoard 12.5 mm (Product Data Sheet) — Manufacturer data sheet listing 12.5 mm board sizes including 1200 × 2400 mm and 900 × 1800 mm, tapered and square edge options, to EN 520 Type A.
• British Gypsum Gyproc WallBoard 9.5 mm (Product Data Sheet) — Manufacturer data sheet confirming the 9.5 mm thickness in sizes including 900 × 1800 mm and 1200 × 2400 mm, tapered and square edge, to EN 520 Type A.

Review status: Formulas and conversions covered by automated tests; measurement practice pending human trade review.

This guide supports planning only. It does not specify structural design, code compliance, or a supplier quotation.