Practical project guide
How to Calculate Drywall
Learn how to estimate drywall sheets for simple rectangular walls.
Start with wall area
For a simple rectangular room, calculate the four-wall area as 2 × (length + width) × wall height. Subtract major openings such as doors and windows when they are large enough to materially change the estimate.
Convert area to sheets
Multiply the sheet length by its width to find the coverage of one sheet. Divide the required wall area by that sheet area and round up. Add a project-appropriate allowance for offcuts and damage.
Worked example
A 5 m × 4 m room with 2.4 m walls has 43.2 m² of gross wall area. Subtracting 6 m² of openings gives 37.2 m². A 2.4 m × 1.2 m sheet covers 2.88 m². With 10% allowance, the planning area is 40.92 m², or about 15 sheets.
Important: Board type, thickness, fire/acoustic requirements, ceiling layouts and framing details may affect the actual material take-off.