Drywall Calculator

A 1200 × 2400 mm sheet covers 2.88 m², so a 3 × 2.7 m partition with two faces is about 16 m² and needs six sheets — five if the room height divides neatly and you do not count the offcuts. The calculator rounds up because half a sheet is not a purchase option, and a wall finished with a vertical offcut strip looks exactly like a wall finished with a full sheet until it is painted.

Studs are set at 600 mm centres for a reason: that is the width the sheet spans and the spacing the board is rated for. A 3 m wall has 6 studs including the ends; moving to 400 mm centres for a heavy tile finish changes the count, not the area.

Screws run at about 30 to 40 per sheet at 300 mm along edges and 200 mm in the field. Joint compound is about 0.4 to 0.5 kg/m² for three coats over taped joints, and the tape itself is about 1.2 m per square metre of board for a normal partition — a number almost always left out and always needed before the first board goes up.

Sound insulation and a second layer change the arithmetic: a double layer doubles the sheet count and adds a second set of screws, while the joint compound per square metre stays roughly the same because the joints are the same length.

Measure the partition length and height, multiply, then double it for a two-sided wall. Deduct openings over 2 m² but not small ones: the cut-off pieces around a socket are waste anyway, and the board count barely changes. For ceilings, the sheet count is the same arithmetic but the waste is higher because every sheet is cut around lights and vents.

The single biggest error is forgetting the second face. A 10 m² partition is 20 m² of board, and the difference between ordering for ten and for twenty is a second trip to the supplier with a trailer.