What this calculator does
Drywall sheets needed works out plasterboard sheets for a room, allowing for openings and waste. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaSheets = ⌈(perimeter × height − openings) × (1 + waste%) / sheet area⌉
The inputs explained
| Field | What to enter |
|---|---|
| Room length (m) | A number, measured in m. Starts at 5. |
| Room width (m) | A number, measured in m. Starts at 4. |
| Wall height (m) | A number, measured in m. Starts at 2.4. |
| Doors | A number. Starts at 2. |
| Windows | A number. Starts at 2. |
| Sheet size | Choose from 1200 × 2400 mm, 1200 × 3000 mm, 1200 × 3600 mm. |
| Waste allowance (%) | A number, measured in %. Starts at 10. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with room length
Every other input is held at the calculator’s starting values while room length varies. Select any row to load that scenario into the calculator.