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Drywall Calculator

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Enter your total wall and ceiling area to find how many sheets of drywall you need, plus estimated screws, joint compound, and tape.

Drywall Calculator

Live
Sheets needed
14
Screws (1 lb box ≈ 320)
2 boxes
Joint compound
2 buckets
Screw and compound estimates use common rules of thumb - actual use varies by finish level and installer.

The formula

Sheets needed = ceiling( (Area x (1 + Waste %)) / Sheet size )
Example

400 sq ft of wall and ceiling area, standard 4x8 (32 sq ft) sheets, 10% waste: 400 x 1.10 = 440 sq ft needed, / 32 = 13.75, rounds up to 14 sheets.

Step-by-step guide

  1. Measure total wall and ceiling area to be covered, in square feet.
  2. Choose your sheet size - larger sheets mean fewer seams but are heavier and harder to maneuver alone.
  3. Read the sheet count, plus rough estimates for screws and joint compound to finish the job.

Choosing a sheet size

Standard 4x8 sheets are the most common and easiest for one or two people to handle. Larger 4x10 or 4x12 sheets mean fewer seams to tape and mud - which can mean a smoother finish and less labor - but they're heavier, harder to maneuver in tight spaces, and may need extra hands or a lift for ceiling installation.

Common mistakes

Forgetting the ceiling in a room-wide drywall project - it's easy to only measure wall area and miss a significant chunk of square footage overhead.
Using standard drywall in a bathroom, kitchen, or other high-moisture area - moisture-resistant ("green board") or cement board is typically recommended for those locations instead.

Frequently asked questions

What thickness of drywall should I use?

1/2 inch is standard for most residential walls and ceilings. 5/8 inch is often used for ceilings (to resist sagging) or where fire-rated assemblies are required, and 1/4-3/8 inch is sometimes used for curved surfaces or over existing walls.

Do the screw and joint compound estimates account for finish level?

These are rough general estimates - a smooth Level 5 finish uses noticeably more joint compound and sanding than a basic Level 4 finish behind paint, so treat these figures as a starting point rather than an exact order quantity.

Should I subtract doors and windows from the area?

You can, but many installers don't bother for small openings, since drywall sheets rarely cut perfectly around them anyway and the waste allowance already provides some buffer. For a large opening, subtracting it can meaningfully reduce sheet count.

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