Drywall Calculator
Turn room and wall measurements into whole drywall sheets, then plan compound, tape, screws and local material costs.
Behind the numbers
How the drywall calculation works
Ceiling area = length × width
Purchase area = net area × (1 + extra % ÷ 100)
Sheets = purchase area ÷ sheet coverage, rounded up
DIYSum combines all sections before whole-sheet rounding. Actual layout, sheet orientation and cuts can change the number of sheets needed.
Compound, tape and screws use editable product or project assumptions and round up to whole purchase units.
Example: a 12 × 14 ft room
At 8 ft high, the four walls total 416 sq ft. The ceiling adds 168 sq ft. With one 3 × 7 ft door and two 3 × 4 ft windows, net drywall area is 539 sq ft. With 10% extra, plan for 592.9 sq ft. Using 4 × 8 ft sheets (32 sq ft each), buy 19 sheets.
Before you buy
Confirm drywall type, thickness, fire/moisture requirements, framing, fastener schedule and local code requirements. Area-based estimates do not optimize sheet layout.
Drywall planning questions
How much extra drywall should I buy?
There is no universal allowance. Ten percent is a common planning starting point, but room shape, cuts, sheet layout and installer experience can change actual needs.
Should I subtract doors and windows?
DIYSum can subtract openings from wall area. For small projects, some installers choose not to subtract small openings because offcuts and layout may consume similar material.
Does this calculator choose drywall thickness or type?
No. It estimates quantities only. Confirm the appropriate thickness, type and installation requirements for your project.
How are compound, tape and screws estimated?
They use the editable coverage, joint-length and fastener assumptions you enter, then round up to whole containers, rolls or packages.