Measure the room
Record room length, width, and wall height in one consistent unit. Measure openings separately so they can be subtracted.
Tool Switcher: Drywall
Project toolsTools
Drywall planning tool
Drywall Calculator
Turn a room's walls and ceiling into whole drywall sheets, plus a planning estimate for screws, joint compound, and tape.
- Walls and ceiling
- US and metric units
- Full material ticket
Drywall planning tool
Drywall Calculator
Estimate drywall sheets, screws, joint compound, tape, and cost.
Methodology
From room dimensions to a material ticket
Find the wall and ceiling area
Wall area is the perimeter times the height. Ceiling area is length times width when the ceiling is included.
Subtract openings and add allowance
Doors and windows are removed from the total, then a planning allowance covers cuts, offcuts, and breakage.
Round up to whole sheets
The planned area is divided by the sheet area and rounded up to whole sheets, since drywall is sold as full panels.
Worked example
A 12 × 14 ft room with 8 ft walls
549 ft²walls + ceiling minus openings
×1.1010% allowance
=603.9 ft²planned area
From 603.9 ft², a 4×8 sheet at 32 ft² each requires 19 whole sheets. That finish also plans for about 626 screws, 4.94 gallons of joint compound, and 203.13 ft of tape.
Frequently asked questions
A second look at the estimate.
How many drywall sheets do I need?
Divide your planned wall and ceiling area by the area of one sheet, then round up to whole sheets. This calculator does that for 4×8, 4×10, and 4×12 panels.
Should I include the ceiling?
Only if you plan to drywall it. Toggle the ceiling on to add length × width, or off for walls only.
How are screws, mud, and tape estimated?
They use planning rates from ASTM C840 and USG estimating guides for a standard three-coat finish. Treat them as estimates and confirm the exact product coverage before buying.
Can I enter metric dimensions?
Yes. Metric mode uses metres for length, width, and height, and square metres for openings. Switching units preserves the same physical room.
How is the cost estimated?
Enter a price per sheet and the calculator multiplies it by the whole-sheet count. Without a price, no cost is shown.
Sources and limitations
This tool estimates drywall sheets and accessory quantities for material planning. It does not select board thickness, fastener schedule, or finish level, and it does not replace framing, fire-rating, or building-code requirements or retrieve live prices.
- Gypsum Association — GA-216 Application and Finishing of Gypsum Panel Products — source for standard sheet dimensions.
- ASTM International — ASTM C840 Application and Finishing of Gypsum Board — reference for fastener spacing used in the screw estimate.
- USG — Sheetrock Brand Estimating Guide — reference for joint compound coverage.
- Concrete calculator — estimate volume for a related structural project.
- Paint calculator — finish the same walls after they are hung and taped.
Accessory quantities (screws, joint compound, tape) are planning estimates for a standard three-coat finish. Confirm the exact product coverage and packaging before ordering.
Last reviewed: September 7, 2026