What is the standard plasterboard size in the UK?

The standard plasterboard sheet in the UK is 2400 × 1200mm (8ft × 4ft), which covers 2.88 m². This is the most common size stocked at B&Q, Screwfix, and builder's merchants. British Gypsum and Knauf both produce boards in this size.

What thickness plasterboard should I use?

12.5mm is the standard thickness for most UK walls. Use 9.5mm for ceilings or where you need a thinner board (e.g., over existing plaster). Use 15mm for enhanced fire resistance or sound insulation. Building regulations may specify minimum thicknesses for certain applications.

How do I calculate plasterboard for a room?

Measure the perimeter of the room (2 × length + 2 × width), multiply by the ceiling height to get total wall area, then subtract door and window openings. Divide by the sheet area (2.88 m² for standard boards) and add 10% for wastage and cutting. If you are fixing boards with dot and dab, use our Dot and Dab Calculator to work out adhesive quantities too.

Should I use tapered edge or square edge plasterboard?

Tapered edge (TE) boards are the standard for most wall and ceiling applications. The tapered edges allow jointing tape and compound to sit flush. Square edge (SE) boards are used when the entire surface will be skim-plastered over. Use our Skim Coat Calculator to work out how much multi-finish plaster you need for skimming plasterboard.

How much does plasterboard cost in the UK?

Standard 2400 × 1200mm × 12.5mm plasterboard typically costs between £5 and £10 per sheet at trade prices (2024). Prices vary by supplier, quantity, and whether you buy from a builder's merchant or retail outlet. Specialist boards (fire-rated, moisture-resistant) cost more.

Plasterboard Calculator — How Many Sheets Do I Need?

Calculate the number of plasterboard sheets per square metre for your walls. Uses UK standard board sizes from British Gypsum and Knauf.

Room Length

Room Width

Ceiling Height

Standard UK ceiling height is 2.4m

Door Openings

Each door deducts 1.6 m²

Window Openings

Each window deducts 1.2 m²

Plasterboard Size

Board Thickness

12.5mm is standard for most UK walls

Include wastage allowance

Adds 10% extra for cutting and breakage

Wastage Percentage

10% is standard; use 15% for complex rooms

Price Per Sheet (optional)

Enter your supplier price for a cost estimate

How We Calculate This

Our plasterboard calculator works by calculating the total wall area of your room and dividing it by the area of your chosen plasterboard sheet size. We deduct standard UK door and window opening sizes to give you an accurate sheet count.

The formula

Sheets needed = (Perimeter × Ceiling height - Openings) ÷ Sheet area × Wastage factor

We use standard UK opening sizes: doors are calculated at 1.6 m² (0.8m × 2.0m) and windows at 1.2 m² (1.2m × 1.0m). These are typical UK sizes but you can adjust the number of openings to match your room.

Sheet sizes

2400 × 1200mm: 2.88 m² — the UK standard, fits through most doorways
2400 × 900mm: 2.16 m² — narrower board for tight spaces
3000 × 1200mm: 3.60 m² — for rooms with higher ceilings, reduces horizontal joints

The 10% wastage allowance accounts for cutting, breakage, and fitting around obstacles. For rooms with many corners or complex shapes, consider increasing wastage to 15%.

Frequently Asked Questions

Related Calculators

Plaster Coverage Calculator

Calculate how many bags of plaster you need for any wall or ceiling area.

Skim Coat Calculator

Calculate multi-finish plaster needed for skim coating walls and ceilings.

Rendering Calculator

Calculate sand and cement quantities for external rendering.

Dot and Dab Calculator

Work out adhesive needed for dot and dab plasterboard fixing.

Plaster Bead Calculator

Calculate angle bead and stop bead lengths for your plastering job.

Last updated: February 2026

All calculations are estimates. Verify with your supplier.