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Calculation Machine

Drywall Calculator

Sheets, screws and compound needed.

Reviewed by the Calculation Machine team · How we check our maths

Your values

ⓘ Live results

Results
Sheets needed
21
Total area with waste
642 sq ft
Screws (approx.)
756
Joint tape
257 ft
Joint compound
34 gallons

Quick answer

Divide total wall and ceiling area by the sheet size, then add 10% waste plus screws, tape and compound.

Worked example

Worked example

Using the values the calculator loads with.

Inputs

  • Room length14 ft
  • Room width12 ft
  • Wall height8 ft
  • Sheet size4×8 (32 sq ft)
  • Include ceiling?Yes

Result

  • Sheets needed21
  • Total area with waste642 sq ft
  • Screws (approx.)756
  • Joint tape257 ft
  • Joint compound34 gallons

How to use the Drywall Calculator

  1. 1Measure room length, width and wall height.
  2. 2Choose the sheet size you will buy.
  3. 3Include the ceiling if you are boarding it.

Frequently asked questions

Should I subtract windows?

Only for large openings — the waste allowance usually covers small ones.

Which thickness?

1/2 inch for walls, 5/8 inch for ceilings and fire-rated assemblies.

About this calculator