Interior surfaces

Drywall Calculator

Enter the total area of wall and ceiling you're covering. A standard 4×8 sheet is 32 square feet. We add 10% for cuts and offcuts.

At a glance

Covers per 4×8 sheet
32 sq ft
Waste allowance
+10%
Answer in
sheets (4×8)

100 sq ft needs:

4 sheets (4×8)

Includes a 10% allowance for waste.

A 4×8 sheet covers 32 sq ft; a 4×12 covers 48. Add compound, tape and screws separately. Figure roughly one 5-gallon bucket of joint compound per 500 sq ft.

Interior surfaces

Measure the room, not the wall

Paint, flooring and tile all get bought by total area with an allowance on top, and the allowance is where people come up short. Doorways, closets and cuts add up faster than the walls do.

How this is worked out

No hidden fudge factor. This is the whole calculation.

  1. Length times width gives the area in square feet.
  2. That area is divided by 32 square feet, which is what one covers, to give the sheets (4×8).
  3. A 10% allowance is added on top for cuts, offcuts and odd shapes.
  4. The total rounds up, since you cannot buy part of a sheets (4×8).

Common questions

How much drywall do I need?
Enter the total area of wall and ceiling you're covering. A standard 4×8 sheet is 32 square feet. We add 10% for cuts and offcuts. Enter your measurements above and this calculator gives you the amount, including a waste allowance where it applies.