How many plasterboard sheets for a room?

Use the plasterboard calculator to get an accurate count for your room. This guide explains the two estimation methods.

Which method is better?

The layout method is more accurate because it accounts for cut-outs: a sheet with a door opening still uses a full sheet. The area method may underestimate.

Use whichever gives the higher number. Our calculator shows both and recommends the larger.

Standard sheet size

The calculator default is 1200mm × 2400mm (2.88 m² per sheet), listed by British Gypsum for Gyproc WallBoard 12.5mm and shown as 2.88 m² on the matching B&Q listing.

The same British Gypsum article list also includes 1200mm sheets at 2300, 2500, 2700, 2800, 3000 and 3600mm, plus 900mm sheets at 1800 and 2400mm. Pick the size you can actually buy.

Example: 4m × 3m room

For four walls, 2.4m high, using 1200 × 2400mm sheets:

• Two 4m walls: 4 sheets each (4 ÷ 1.2 = 3.33, round up to 4 columns × 1 row)
• Two 3m walls: 3 sheets each (3 ÷ 1.2 = 2.5, round up to 3 columns × 1 row)
• Total: 14 sheets for walls

Add ceiling (4 × 3 = 12 m² ÷ 2.88 = 5 sheets) if boarding it: 19 sheets total.

Should I add waste allowance?

It's up to you. The layout method already accounts for cut-outs, but you might want extra for breakages or mistakes. There's no standard waste percentage for plasterboard — decide based on your experience and site conditions.

How many screws per sheet?

British Gypsum guidance:

• Partitions: 300mm centres (200mm at external angles)
• Ceilings: 230mm centres in the field, 150mm at board ends

Screw length: board thickness plus 10mm into metal studs, or plus 25mm into timber.

Vertical or horizontal?

The calculator's layout method assumes vertical boards on walls (sheet width across the wall, sheet length up the wall). That is a planning estimate, not a fixing specification. Follow the board manufacturer for joint layout.

Sources: British Gypsum Gyproc WallBoard product page and screw-fixing FAQ, both read 26 October 2026.