Drywall Calculator — Sheets Needed for Walls or Ceilings
Drywall (plasterboard) comes in standard sheet sizes. Getting the count right before your delivery avoids costly re-orders and delays. Enter your total area and sheet dimensions to find out exactly how many boards you need.
How we calculate
Sheet area = width × height. Sheets = ⌈(total area ÷ sheet area) × (1 + waste %)⌉.
Worked example
40 m² area, 1.2 m × 2.4 m sheets (2.88 m²), 10% waste. Sheets = ⌈(40 ÷ 2.88) × 1.1⌉ = 16 sheets.
Common mistakes
- •Not accounting for cuts around doors, windows, and electrical boxes — add at least 10% waste.
- •Ordering all sheets in one thickness — walls typically use 12.5 mm, ceilings 12.5 mm or 15 mm.
- •Forgetting to order jointing compound and screws at the same time.