Drywall Calculator sizes a boarding job from either a room's dimensions or a total area you have already measured. Sheets are the straightforward part — area divided by sheet area, rounded up, with a waste allowance for the offcuts around doors and windows. The finishing materials are estimated from long-standing per-square-foot rules: roughly 0.053 pounds of joint compound and 0.4 linear feet of tape per square foot of board, and 32 screws per sheet on walls framed at sixteen inch centres, rising to 36 on a ceiling where fastening is denser. Four stocked sheet sizes are offered, because longer panels mean fewer butt joints to tape.
Features
Sheet count from room dimensions or a measured total area
Four stocked sheet sizes from 4×8 up to 4×12
Waste allowance for cuts around doors and windows
Joint compound and tape estimated from the boarded area
Screw count adjusted for the denser ceiling fastening pattern
Optional ceiling coverage added from the room footprint
US and metric dimensions
Optional cost estimate from a price per sheet
How to use the Drywall Calculator
Choose whether to enter room dimensions or a total surface area
Pick the sheet size you plan to buy
Set a waste allowance and decide whether the ceiling is included
Read the sheet count and finishing materials, and add a price per sheet
Example
Input
12 × 10 ft room, 8 ft ceiling, 4×8 sheets, 10% waste
Output
352 sq ft · 12 sheets · 18.7 lb compound · 141 ft tape · 384 screws
Walls only in an average bedroom, boarded with standard 4 by 8 foot sheets.
Common errors & troubleshooting
The sheet count seems high for a room with big windows. — The room mode measures gross wall area. Switch to the total-area mode and enter the wall area with the openings already subtracted if they are large enough to matter.
Unsure whether longer sheets are worth the handling. — Compare the sheet counts. A 12 foot panel spans most walls in one piece, which removes butt joints — the hardest joints to finish invisibly — so fewer, longer sheets usually means a better result.
The joint compound estimate does not match what you used. — Compound consumption varies enormously with technique and finish level. A level 5 skim coat can use several times the figure here, which assumes taping and three coats over the joints only.
The screw count looks low. — It assumes framing at sixteen inch centres. Twenty-four inch centres use fewer screws per sheet; a ceiling or a fire-rated assembly with a specified pattern will use more.
Frequently asked questions
How many drywall sheets do I need for a room?
Divide the surface area by the sheet area and round up, then add ten percent for waste. A 12 by 10 foot room with 8 foot ceilings has 352 square feet of wall, which is eleven 4 by 8 sheets before waste and twelve after.
What size drywall sheet should I use?
The longest you can handle. A 4 by 12 sheet spans most walls in one piece, eliminating butt joints, which are the hardest to hide. 4 by 8 sheets are easier to carry and fit through doorways but leave more joints to tape.
How much joint compound does drywall need?
Around 0.053 pounds per square foot of board for taping and three coats over the joints — roughly a 4.5 gallon bucket per 900 square feet. A full skim coat over the whole surface uses considerably more.
How many screws per sheet of drywall?
About 32 for a wall sheet on framing at sixteen inch centres, and 36 or more on a ceiling where the fastening pattern is denser to carry the weight. Codes for fire-rated assemblies specify their own spacing.
Do the room measurements I enter leave my device?
No. Everything is calculated in your browser and no dimensions or prices are transmitted.
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