Estimate how many drywall sheets a room needs

The job

Drywall is bought by the sheet, and sheets come in fixed sizes. The estimate needs wall area minus openings, then a waste margin for cuts and breakage.

Room in, sheets out

Enter length, width and ceiling height; count doors and windows; set waste (10% is the usual default). The result lists sheet counts for common sizes — pick the size your supplier stocks.

• The estimate covers one face of each wall. Boarding both sides? Double it.
• The ceiling checkbox adds the ceiling as a second rectangle — it is on by default, so untick it for walls only.

Sanity check

A 4 m × 5 m room with a 2.4 m ceiling, one door and two windows is about 38 m² of wall — roughly 15 sheets of 2400×1200 mm at 10% waste (23 if you also board the ceiling). If your number is far off, re-check whether you entered metres in a feet field.