Drywall Calculator
Enter the total area to cover and your sheet dimensions to find how many sheets to buy.
How drywall quantity is calculated
Each sheet covers an area equal to its width × height. Dividing your total area to cover by this per-sheet area gives the exact number of sheets needed with zero waste.
In practice, sheets get cut to fit around corners, openings, and odd room shapes, so a waste allowance (commonly 10%, more for complex rooms) is added before rounding up to a whole number of sheets.
Frequently asked questions
What's a standard drywall sheet size?
A common size is 1.2 m × 2.4 m (about 4 ft × 8 ft), though sizes vary by manufacturer, region, and project — always confirm your specific sheet's dimensions.
Should I measure walls or ceilings separately?
You can combine wall and ceiling area into one total if you're using the same sheet size and thickness for both, or run the calculator separately for each if they differ.
How much extra should I buy for waste?
10% is a reasonable starting point for a straightforward rectangular room; rooms with many corners, openings, or an irregular shape typically need more, since they create more offcuts.