Drywall Calculator
Estimate how many plasterboard or drywall sheets a wall or ceiling needs, including a cutting allowance.
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Formula and method
The wall area is reduced by openings and increased by the waste allowance, then divided by the area of one sheet. The result is rounded up to whole sheets.
How to measure the inputs
- Measure the wall length and height, then count identical walls.
- Add up the area of doors and windows you want to deduct.
- Measure the sheet you will buy: 1.2 m × 2.4 m and 1.2 m × 3 m are the common sizes.
Worked example
Wall length 16.4 ft; Wall height 9.84 ft; Wall count 1; Openings area (optional) 6.46 ft²; Sheet length 3.94 ft; Sheet width 7.87 ft; Waste 5 % → Plasterboard sheets: 6
Practical tips
- Order sheets long enough to span a wall in one piece where possible.
- Store sheets flat and off the floor until they are fitted.
- Use the correct board type for wet rooms and fire-rated walls.