Plasterboard calculator: how many boards do I need?

Choose walls or ceiling, put in your sizes and pick a board. You'll see how many boards to order and roughly how many bags of multi-finish you'll need to skim them.

Area to board
31.6 m²
Boards to order
13
Multi-finish (25kg)
4 bags
Board size
2400 × 1200mm

Finish plaster is based on about 10m² per 25kg bag at 2mm. Check the bag, because coverage varies by brand and wall.

How it works

  1. 1For walls, add up the length of every wall you're boarding and measure the height. For a ceiling, measure the room length and width.
  2. 2Take off doors and windows. A standard internal door is about 1.6m² and an average window is about 1–1.5m².
  3. 3Pick your board. A 2400 × 1200mm (8×4) board covers 2.88m², while a 1800 × 900mm (6×3) board covers 1.62m². 6×3s are easier to handle on your own, especially on ceilings.
  4. 4Add a cuts allowance. 10% is usual for a room with a few openings. Go for 15% if there are lots of reveals or awkward angles.
  5. 5Check the finish plaster. Multi-finish at about 2mm covers roughly 10m² per 25kg bag.

Now find the cheapest place to buy

Take your quantities across to Price Planter and compare them across UK builders' merchants — including whether splitting the order across two merchants works out cheaper.

Compare material prices

Board and plaster quantities are a guide based on typical UK trade figures. Confirm them with your plasterer and merchant before ordering.

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