Drywall calculator.
How many sheets of drywall does a room need? Enter its size and we count the sheets, with an allowance for waste.
It's free, and it runs in your browser. Nothing you type is sent anywhere or saved.
Enter the room.
Measuring rooms from a floor-plan PDF? QWIKIT Plans is being built to do it for you.
Join the waitlistHow it's worked out.
Wall area is the room's perimeter times the ceiling height, less 20 sq ft for each door and 15 sq ft for each window. The ceiling, if you include it, is the length times the width.
We add your waste allowance (10 per cent is a common allowance for cuts and breakage), divide by the area of one sheet, and round up to whole sheets.
What it can't tell you.
- It counts by area, not by layout. A room with many short walls, odd angles or lots of cuts can need more sheets than the area suggests.
- It doesn't count screws, tape, joint compound or corner bead, and it doesn't pick a thickness or type for you. Ask your supplier.
- Some trades don't take small openings off the area. If you don't, set doors and windows to 0.
These are estimates from common rules of thumb. Check them against your supplier's advice and your own plans before you order.
Questions.
How many sheets of drywall do I need for a 12 by 10 foot room?
With 8 ft ceilings, one door and one window, the walls come to 317 sq ft. Adding the ceiling makes 437 sq ft, and with 10 per cent waste it is about 481 sq ft, which is 16 sheets of 4 × 8 ft drywall. For the walls only it is 11 sheets.
How much waste should I allow for drywall?
The calculator starts at 10 per cent, a common allowance for cuts and breakage. A room with many corners, angles or short walls may need more. You can change the number.
Does the calculator subtract doors and windows?
Yes. It takes 20 sq ft off for each door and 15 sq ft off for each window. If you don't deduct openings, set doors and windows to 0.
Which drywall sheet sizes can I choose?
4 × 8 ft (32 sq ft), 4 × 10 ft (40 sq ft) and 4 × 12 ft (48 sq ft). The sheet count changes with the size you pick, so check what your supplier stocks.
Is what I type saved or sent anywhere?
No. The calculator runs in your browser. Nothing you type is sent anywhere or saved.
More free calculators.
What if you didn't have to do this by hand anymore?
You just typed a room's measurements in yourself. QWIKIT Plans is desktop software for Windows and Mac that we're building to read rooms, walls and openings from a floor-plan PDF instead. The app is not released yet, and joining the waitlist is free.
Join the QWIKIT Plans waitlist