How many sheets of drywall do I need
Count the area, divide by the area of one sheet, add a waste allowance and round up. Here is the method with a worked example.
Find the area to cover
Drywall is sold in sheets, and a common sheet is 4 feet by 8 feet, which is 32 square feet. Other sizes exist, so check the size at your supplier before you count.
- Measure the length of each wall and the height of the room.
- Multiply length by height for each wall, then add the walls together.
- Measure the ceiling length and width, and multiply.
- Add the wall area and the ceiling area.
- Large openings, such as a wide patio door, can be taken out. Small windows and doors are usually left in, because cut-outs make waste.
Turn the area into sheets
Divide the total area by the area of one sheet. You will get a number with a decimal. Then add a waste allowance, because cuts, breakage and odd shapes use up board. Pick an allowance you are comfortable with and use it the same way each time. Then round up to whole sheets.
Worked example: a small room (made-up figures)
The room is 12 feet by 10 feet with an 8-foot ceiling. The walls add up to 44 feet around, times 8 feet high, which is 352 square feet. The ceiling is 120 square feet. The total is 472 square feet.
472 divided by 32 is 14.75 sheets. Add a 10% waste allowance (an example, not a rule) and you get about 16.2. Round up and buy 17 sheets.
At $18 a sheet that is $306 before Tax A and Tax B. Add the tax lines you take from the official source on top.
Do not forget the rest of the order
Sheets are only part of the list. Write down the other items before you leave for the supplier:
- Screws, in the length that suits the board thickness.
- Joint compound and tape.
- Corner bead for outside corners.
- Delivery, if the sheets are too long for your truck.
Long sheets are hard to carry through tight halls. Check the route before you order a size.
Check your figures with the drywall sheet calculator
Type the same figures into the drywall sheet calculator if you want a second check. It is free to start, you type every figure yourself, and nothing is sent. Save the count with the job notes so the order is ready next time.
Built in Canada for Canadian rules.
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Estimate, not tax or legal advice. General information for planning. All figures are made-up examples. You type every figure, and you take every tax name and rate from the official source. Nothing is sent.