Calculate How Much Drywall You Need


So you’ve decided to hang drywall. The most important aspect of preparing for your drywall job is determining how much drywall you actually need. Why is this so important? You don’t want to buy too little drywall and have to go back to the store in the middle of the job, and you don’t want to waste money buying too much. Accurate measurements and a little bit of math will ensure that you have just the right amount of drywall. Don’t skimp on this part, and check your math a couple of time.

You’ll need a tape measure and a pad and pencil, or calculator, to calculate how much drywall you need for your job.

What is the Height of Your Ceiling?

Determining the height of your ceiling will be the first step in calculating the correct amount of drywall for your job. Drywall comes in various sizes, usually 4 feet wide and 8, 12, or 16 feet long. If your ceiling's length can be divided by one of those lengths, you'll want those boards to conserve waste and cutting boards into pieces. Using your tape measure, measure from the ceiling to the floor and write the number down on your pad.

What is the Width of Each Wall?

Using your tape measure, measure each wall from end to end. Mark these numbers in your pad as well. If you have standard width walls, you will hang the drywall vertically, 4 feet across and 10 feet down. If you are looking to hang drywall in a very large room, it may make more sense to hand the drywall horizontally, 4 feet down and 10 feet across. In the modern homes built today, great rooms and basements often require drywall to be hung horizontally. Note which way you plan on hanging the dry wall.

Do the Math!

First, you have to determine the square footage of each wall. In order to calculate the square footage you will multiply width by length. If your ceiling height is 10 feet and the width of the first wall is 10 feet, you’ll multiply 10 by 10.

Now that you have the square footage of the wall, you have to determine the square footage of each sheet of drywall. You know that the wall is 100 square feet. Since the ceiling height is 10 feet, you already know that you have to use drywall sheets that are 4x10. Multiply the width by the length of the drywall to determine its square footage. 4 times 10 equals 40. That means that every sheet of drywall will cover 40 square feet.

Now you have to use the results of the last two math problems to determine how many sheets will be needed for each wall. Divide the square footage of the wall by the square footage of the drywall. In this case, you will divide 100 by 40. 100/40 equals 2.5. That means that you will need three sheets of drywall to complete that one wall. Remember to always round up!

Once you have calculated the square footage of each wall and divided it by the square footage of your drywall boards, you will add the four numbers together to determine the exact number of sheets needed for the entire room.