How it works
Give it the area and your sheet size, and it counts the sheets — waste included.
Enter the area
Type the total square footage, or switch to room size to estimate the walls (and ceiling) for you.
Pick sheet size
4×8, 4×10 or 4×12. Bigger sheets mean fewer seams to finish.
Get your sheet count
See how many sheets to buy, plus a rough joint-compound estimate.
Counting drywall the right way
Drywall math is a simple division: the area you're covering divided by the area of one sheet. A standard 4×8 sheet is 32 square feet; a 4×10 is 40 and a 4×12 is 48. Bigger sheets cover faster and leave fewer seams to tape and mud — but they're heavy and awkward, so one person working alone often prefers 4×8s.
Then add waste. Every door, window, outlet and corner means a cut, and the offcuts rarely fit the next spot. Ten percent is the standard allowance; bump it up for a room chopped up by closets and openings. Rounding up to whole sheets matters too — you can't buy two-thirds of a sheet.
The calculator also gives a rough joint-compound figure so you're not caught short, but treat it as a guide: the real amount depends on how many coats you do and how smooth a finish you're after.
Frequently asked questions
How many sheets for a 500 sq ft area?
With 4×8 sheets and 10% waste, about 18 sheets. With 4×12 sheets, about 12.
How big is a sheet of drywall?
4×8 = 32 ft², 4×10 = 40 ft², 4×12 = 48 ft². All are 4 feet wide.
4×8 or 4×12?
4×12 means fewer seams to finish but is heavy to handle. 4×8 is easier for one person.
Does this include the ceiling?
In "Room size" mode you can tick a box to add the ceiling. In "Total area" mode, just include it in your square footage.
More material calculators
Estimates are for planning only. The joint-compound figure is a rough guide; confirm quantities before buying.