Drywall Calculator
Estimate the number of drywall panels needed from the actual surface area, panel size and waste allowance.
Project details
Estimate
This calculator intentionally does not estimate joint compound, tape or fasteners because those quantities depend on the finishing system and installation method.
How drywall panel quantity is estimated
Start with the total surface area that will actually receive drywall. Add a waste allowance for cuts and off-cuts, then divide by the square-foot coverage of one panel.
Panel coverage
A 4 × 8 ft panel covers 32 ft², a 4 × 10 ft panel covers 40 ft², and a 4 × 12 ft panel covers 48 ft² before cuts and waste.
Worked example
Drywall calculator FAQ
Should I subtract doors and windows?
If your surface-area measurement already excludes openings, enter that net area. If you measured entire walls, you can subtract openings before entering the number.
Why are tape and joint compound not included?
Panel layout, joint count, bead, finishing level and product system all affect finishing-material use. A simple square-foot formula can give a false sense of precision.
Does a larger panel always reduce waste?
Not necessarily. Panel orientation, wall height, framing layout and handling constraints all affect the best panel size.