Free Drywall Calculator: Sheets, Mud and Tape
Enter the total length of the walls, the wall height and the ceiling area. Doors and windows come out of the wall area. You’ll get sheets for walls and ceilings plus screws, tape, mud and corner bead. These are the same rules LaraKey’s takeoff calculator uses.
Materials
Estimates only. Measure on site and check with your supplier before you order.
How to calculate drywall
Wall area = Wall length × Height − (Doors × 20 sq ft) − (Windows × 15 sq ft)
Sheets = Area ÷ Sheet size (32 sq ft for 4×8, 48 for 4×12) + waste, rounded up
Screws = 32 per 4×8 wall sheet and 40 per ceiling sheet, 1,000 per box
Joint tape = 37 ft per 100 sq ft of board, 500 ft rolls
Joint compound = 1 bucket per 450 sq ft of board
Corner bead = 1 piece per 8 ft of height at each outside corner
Examples
A 12 × 14 ft bedroom
52 ft of wall × 8 ft = 416 sq ft, less 1 door and 2 windows (50 sq ft) = 366 sq ft → 13 sheets of 4×8 with 10% waste. The 168 sq ft ceiling needs 6 sheets. That’s 1 box of screws, 1 roll of tape and 2 buckets of mud.
A basement with 9 ft walls on 4×12
120 ft of wall × 9 ft = 1,080 sq ft, less 2 doors and 4 windows = 980 sq ft → 980 ÷ 48 × 1.1 = 23 sheets of 4×12.
Drywall Calculator: common questions
How many sheets of drywall do I need for a room?
Add the wall area and the ceiling area, take out doors and windows, and divide by the sheet size: 32 sq ft for a 4×8 or 48 sq ft for a 4×12. Add 10% for waste.
Should I use 4×8 or 4×12 sheets?
4×12 sheets mean fewer seams and less taping on long walls and ceilings, but they’re heavier and need more hands. 4×8 is easier in small rooms and tight stairways.
How much waste should I add for drywall?
About 10% for a typical room. Rooms with lots of corners, angles or openings can need 15%.
How much joint compound do I need?
Roughly one 4.5-gallon bucket of all-purpose compound for every 450 sq ft of board, for three coats.
How many drywall screws per sheet?
About 32 for a 4×8 sheet on walls and 40 on ceilings, where screws go closer together.
Do I subtract doors and windows?
Yes. The calculator takes out 20 sq ft per door and 15 sq ft per window. Many pros leave small openings in to cover waste.
Does this include ceilings?
Yes. Enter the ceiling area in square feet (length × width of the room).
Are these numbers exact?
They’re estimates. Measure on site and confirm before you order.
Talk to a person who knows remodeling.
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