🧱 Drywall Calculator
Enter your room’s perimeter, ceiling height, and door/window area to estimate how many drywall sheets, screws, and buckets of joint compound you will need.
What This Calculator Does
The drywall calculator estimates how many sheets of drywall you need to cover a room’s walls (or ceiling), based on the total wall length, wall height, the area taken up by doors and windows, and the sheet size you plan to use.
How the Calculation Works
First, gross wall area is found by multiplying total wall length (the room’s perimeter) by wall height. Door and window area is then subtracted to get net area, since drywall is not needed there. A waste allowance is added on top to account for cuts, mistakes, and irregular spaces, and the result is divided by the square footage of one sheet, then rounded up to a whole number of sheets. Rough estimates for drywall screws (about 32 per standard sheet) and joint compound are included as a starting point.
Tips for Ordering
- A 10 percent waste allowance is typical for simple rectangular rooms; use 15 percent or more for rooms with many corners, angles, or vaulted ceilings.
- Standard 1/2 inch drywall is common for walls, while 5/8 inch is often used on ceilings or for fire-rated assemblies.
- Buy a few extra sheets beyond the calculated amount to have spares for repairs or patches later.
Note: Figures are general planning estimates. Always check local building codes and consult a qualified contractor for structural or fire-rating requirements.