Boarding a room
A room with 40 ft of wall at 8 ft high is 320 ft²; in 4×8 sheets that is about 11 sheets including waste.
Drywall Calculator
Drywall - figures update as you type, nothing leaves your browser.
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Figures update as you type. Nothing you enter leaves this tab, and no values are stored.
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Browse all specialized calculatorsAbout Drywall Calculator
A drywall calculator estimates how many sheets a room needs from the wall length and height and the sheet size you are using. Drywall comes in fixed sheets - most commonly 4×8 feet, or 32 square feet each - so the real question is how many of those cover your walls, with an allowance for the offcuts every hang produces. Buying by guesswork means either a second trip mid-job or a stack of leftover sheets taking up the garage. The tool divides your wall area by the sheet size and adds about 10% for cuts, waste and the pieces you inevitably ruin. Enter the total length of wall to be covered - for a whole room, that is the perimeter - and the height. If you are also boarding the ceiling, run it again with the ceiling dimensions. Larger 4×12 sheets mean fewer joints to tape but are heavier to handle, which is the trade-off behind the sheet-size choice.
Using Drywall Calculator
- Add the lengths of walls with the same height and enter that total in feet. For walls of different heights, calculate each group separately so a tall section is not averaged away.
- Enter sheet area in square feet: a 4 by 8 ft sheet is 32, while a 4 by 12 ft sheet is 48. The calculator applies a 10% cutting allowance and rounds the result up to complete sheets.
- Estimate ceilings separately using their length and width as the two area inputs. Record that result before returning to wall measurements, and check which offcuts can realistically be reused.
Where drywall calculator helps
Before you use the result
- The sheet count is based on area. It does not optimize board orientation, joint placement or the size of offcuts. A narrow strip may need another sheet even when the leftover area appears sufficient.
- For 320 square feet and 32-square-foot sheets, the model gives 11 sheets after its allowance. Do not automatically add another 10% for the same waste. Revise the order only for layout losses the first allowance does not cover.
- Openings, sheet thickness, moisture resistance and fire-rated assemblies require separate decisions. Subtracting every small opening can understate the material needed because cutout pieces may not be reusable elsewhere.
Questions about Drywall Calculator
What size drywall sheet should I use?
4×8 ft (32 ft²) is standard and easy to handle; 4×12 ft means fewer joints but is heavier. Enter whichever you are buying and the tool counts the sheets.
Is my data saved or uploaded?
No. Drywall Calculator calculates the result entirely in this browser; the values you enter are not stored or sent to a server.
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