Measure walls and ceilings as separate plasterboard surfaces

Measure each surface that receives plasterboard, then group surfaces that use the same sheet specification. A wall and a ceiling may have different products or layer counts, so keep them separate even when the total area is easy to combine.

Calculate a rectangular room

An illustrative room is 4 m long, 3 m wide and 2.4 m high. Its four walls total 2 × (4 + 3) × 2.4 = 33.6 m². A 0.9 × 2.1 m door opening reduces the flat wall-face area to 31.71 m². The ceiling is another 12 m². Reveals or other lined returns have not been included.

Count each lining layer

If the specification requires more than one layer, record the area of each layer and product separately. Do not assume that a two-layer system needs the same cut layout or fixings for both layers. An area calculation does not establish the required fire, acoustic or wet-area system.

Compare area with sheet placement

A 2.4 × 1.2 m sheet covers 2.88 m² before cuts. Dividing 31.71 m² by 2.88 gives about 11.01, so the wall area alone rounds to 12 sheets. Check wall lengths, orientation, joint support and offcut reuse before accepting that purchase count.

Keep the record traceable

The Nowra project record shows how a wall and ceiling takeoff can feed separate material estimates. Use its method as a checking example, while entering your own dimensions and product choices. Order details should identify sheet type, size, thickness and quantity rather than only a total square-metre figure.

Found a measurement or calculation issue? Send the example and your correction.