Plasterboard Calculator

How many plasterboards do I need?

Take the total surface area you're boarding in square metres, add a wastage allowance (10% is a sensible default, more if the room has lots of awkward cuts), then divide by the area of one board and round up. A standard 2400 × 1200 mm sheet covers 2.88 m², so a 20 m² area with 10% wastage works out at roughly 22 m² ÷ 2.88 ≈ 8 boards. This calculator does that sum for you the moment you type your measurements.

What size is a standard sheet of plasterboard?

The most common sheet in the UK is 2400 × 1200 mm (8 ft × 4 ft), covering 2.88 m². Smaller 1800 × 900 mm boards are easier to handle single-handed and useful in tight spaces, while 2400 × 900 mm is a common alternative width. Thickness is a separate choice — 12.5 mm is standard for walls and ceilings, 9.5 mm for curved or lightweight work — but thickness doesn't change how many boards cover the area, so it isn't part of this calculation.

How many screws per plasterboard sheet?

Roughly 20 to 30 drywall screws per standard sheet, depending on stud spacing and whether it's a wall or a ceiling (ceilings get more fixings). This tool estimates around 25 screws per board and then tells you how many 1000-count boxes that adds up to. Fix at about 200–300 mm centres along the studs and keep screws 10–15 mm in from the board edges to avoid crumbling.

What comes after boarding — skim or paint?

Most boarded walls get a plaster skim before they're decorated. Our Plaster & Render Calculator works out the bags of skim, bonding or hardwall you'll need for that stage. Once the wall's finished, our Paint Calculator works out the litres and tins for the topcoat.

Does this tool store my details?

No. Every calculation runs entirely in your browser — nothing you type is uploaded, saved or sent anywhere, and there's no sign-up. Close the tab and it's gone. It's a free estimating aid from BuildMeA, the team that builds websites and lead systems for UK trades.