Plasterboard calculator
Enter the room size, choose a sheet size, and decide whether the ceiling is included.
Measuring in feet and inches? Use the US version
Sheets needed
19 sheets
- Wall area
- 33.5 m²
- Total area
- 49.5 m²
How it works
The calculator adds up the wall area (perimeter × height), takes off about 1.9 m² per door and 1.5 m² per window, and adds the ceiling if you include it. It then adds your cut allowance and divides by the area of one sheet: 2.88 m² for a 2400 × 1200 mm sheet.
Example
With room length 4 m, room width 4 m, wall height 2.4 m, include the ceiling: yes, doors 1, windows 2, sheet size: 2400 × 1200 mm, extra for cuts 10%, the answer is 19 sheets.
Tips before you buy
- Bigger sheets mean fewer joints, but a 2400 × 1200 mm sheet is heavy and awkward to lift onto a ceiling alone.
- Fit the ceiling first, then the walls.
- Use moisture-resistant board in bathrooms and kitchens, and fire-rated board where local rules require it.
Common questions
How many sheets of plasterboard for a 4 × 4 m room?
With 2.4 m walls, one door, two windows and the ceiling, about 19 sheets of 2400 × 1200 mm including 10% extra.
How big is a sheet of plasterboard?
2400 × 1200 mm (2.88 m²) is the most common size. Smaller and longer sheets are available too.
How much extra plasterboard should I buy?
About 10% for a simple room, more for lots of openings and corners.