Home Improvement
Sheets needed
Net surface divided by sheet area, rounded up with a waste allowance.
The Formula
sheets = ceil((wall area + ceiling area - openings) / sheet area x (1 + waste))
Net surface divided by sheet area, rounded up with a waste allowance.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| N | Sheets | sheets | The number of boards to order, a whole number. |
| A_s | Sheet area | square feet | 32, 40 or 48 square feet. |
| O | Openings | square feet | Doors, windows and uncovered areas. |
| w | Waste | decimal | Extra fraction for cuts and damage. |
What Each Symbol Means
Nsheets
Sheets
The number of boards to order, a whole number.
A_ssquare feet
Sheet area
32, 40 or 48 square feet.
Osquare feet
Openings
Doors, windows and uncovered areas.
wdecimal
Waste
Extra fraction for cuts and damage.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate drywall needed page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Drywall Needed, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.