Drywall estimating is simple with just a few basic concepts. If you’re a homeowner working on a DIY repair, or an estimator working on a large commercial project, figuring out how much drywall you need is the critical first step.
In the construction world, you need to complete a quantity takeoff to calculate how much drywall you need for a project.
A takeoff can be as simple as a few sheets of sheetrock, or a multi-million dollar commercial estimate including drywall, steel studs, insulation, exterior sheathing, corner bead, and taping mud.
Measuring Square Footage
When figuring out how much drywall you need for your project, there are a few simple steps to follow.
- Measure the room dimensions – the length of the wall by the wall height to get the total square footage of the surface area you are covering with drywall.
- Next, divide the total square footage of drywall by 32 if you are using 4’ x 8’ sheets of drywall. If you are using 4’ x 10’ sheets, divide by 40. And if you are using a 4’ x 12’ sheet size, divide by 48 st ft.
- Don’t forget to account for waste. Add at least 10% – 15% to your total square foot amount before you total your sheet count.
Estimate Total Drywall Sheets
Now you have a total drywall sheet count, including waste. If you are hanging walls and ceilings, figure the total sq ft. area of the ceiling using the width and length.
Add the number of drywall sheets needed for the walls to the ceiling sheet count. Always double-check your math, there’s nothing worse than ordering drywall for a job and realizing you made a mistake in your estimate.
Estimate Drywall Tape
A quality drywall estimate is not complete with just a sheet count. There are a few more items you’ll want to figure out along with the drywall order.
Drywall tape is applied with joint compound during the taping process. To figure out how many rolls of tape, use the total number of sheets and multiply by the perimeter of one single sheet.
- 4’ x 8’ sheets = 24’ perimeter
- 4’ x 10’ sheets = 28’ perimeter
- 4’ x 12’ sheets = 32’ perimeter
If you need 62 sheets of 4’ x 8’ drywall for your project, multiply 62 by 24’ to get the total amount of tape required.
- 58 x 24 = 1,392 feet of drywall tape
The typical drywall joint tape is sold in rolls of 500 feet. Divide 500 into 1,488 feet for your total roll count.
- 1,392 / 500 = 2.78
Always round up to the nearest full roll. You will need 3 rolls of drywall tape for your project.
Estimate Joint Compound
Drywall requires roughly .05 pounds of joint compound drywall mud per square foot of drywall.
Multiply the total amount of drywall square feet by .05 to get the total pounds of mud required.
Once you have the total pounds of mud, the next step is to decide what type of mud and how many pails.
USG Sheetrock Brand UltraLightweight All Purpose Joint Compound
If using Sheetrock Brand UltraLightweight All Purpose Joint Compound, USG recommends two 4.5 gallon pails of drywall mud per 1,000 square feet of drywall.
Each 4.5-gallon pail of UltraLight drywall mud weighs 36 pounds.
So two 36-pound pails of USG Sheetrock Brand UltraLightweight mud equals about .072 pounds per square foot.
Estimate Drywall Screws and Fasteners
Estimating drywall screws is pretty straightforward. First, you will need roughly one screw per square foot of drywall.
Next, figure out how many pounds of screws you will need.
One pound of drywall screws includes about 230 screws, so divide 220 into the total square feet for the total pounds of screws required.
- 2,800 square feet of drywall = 2,800 screws
- 2,800 screws divided by 230 = 12.17 pounds of drywall screws
- You will need 3 five-pound boxes of drywall screws for 2,800 square feet of drywall or wallboard
- One five-pound box of 1 5/8” drywall screws costs $33, so the total amount for screws will be about $100.
Estimate Corner Beads
Don’t forget the corner bead. Every vertical and horizontal exposed edge of gypsum board will require a corner bead.
Count each corner, and figure on using one full piece of 8’ or 10’ corner bead. If the ceiling height is 9’ 6” high, plan on using 10’ corner bead.
Multiply the number of corners by the height, and add the total footage of soffits and horizontal corner bead.
Add those two numbers together, and divide by either 8 feet or 10 feet.
For example –
- 18 corners 10 feet tall plus 65 feet of soffit
- 180 feet plus 65 feet = 245 linear feet, divided by 10 feet = 24.5
- You will need 25 ten-foot-long pieces of corner bead. Don’t forget to add for some waste.
Estimate Miscellaneous Costs
With the majority of your materials estimated, you still have several items remaining for your drywall project.
Here are a few things you might want to add to your drywall estimate, beyond just material cost, and depending on the type of project.
- Labor costs for hanging and taping drywall
- Sandpaper and sanding supplies
- Drywall finishing and taping supplies
- Drill, drill bits, battery
- Ladders, lifts, and equipment for accessing high ceilings and walls
- Clean up supplies
- Dropcloths, poly, or temporary floor protection
- Dumpsters, waste removal
And the list goes on and on. Each project is unique. Consider every aspect of the job and the special conditions it will require. Think it through.
One thing to remember when estimating how much drywall you will need on your project –
Will you do the drywall installation yourself, or hire someone to perform the work?
It’s important to consider the opportunity cost of a home improvement project, and if you can produce quality results by installing drywall on your own.
Just consider this – Drywall and taping work is not for everyone. Hiring a professional to install drywall and taping might be the best money you ever spend. Enough said.
Commercial Drywall Cost Estimating
You might be a homeowner looking to hang 5 sheets of rock in the basement closet or hang the garage ceiling. But did you know that commercial drywall estimating occurs on the biggest buildings in the world?
A single commercial drywall bid could amount to $20, $30, or $50 million dollars on the largest mega-projects under construction today.
A commercial drywall contractor employs estimators to assemble bids and negotiate contracts for these projects.
Drywall Estimating Mega-Projects
High-rises, airports, data centers, and the latest mega-battery factories require a drywall estimate.
You might be surprised to find out that all the methods discussed above are used in these monster commercial drywall bids.
But instead of scratching the quantities out on the back of an envelope, these bids use powerful computer software to estimate every piece of sheetrock, cornerbead, and screw, required for the drywall job.
Drywall Estimating Software and Calculators
There are dozens of drywall estimating software programs available. There are simple online calculators and complex commercial drywall estimating programs that cost nearly $10,000.
For example –
The Home Depot drywall calculator (free online)
On Center Software cost estimating software ($9,000 per user license)
And there’s everything in between. You can figure most small jobs out by hand, but once a project takes on a certain complexity, it’s best to find a great estimating software program and begin to familiarize yourself with it. Have fun!
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