Free Drywall Calculators

Hanging drywall, patching a ceiling or budgeting a renovation? These free drywall calculators help you work out how many sheets to buy and what the job could cost. Each one shows its formula and a worked example, so you can check the math yourself.

Drywall calculators

Which drywall calculator should I use first?

Most drywall projects follow the same order. The measurements you take once work for every calculator.

1. Measure the room. Write down the length, width and ceiling height, and count the doors and windows.
2. Count your materials. Use the sheetrock calculator to see how many sheets you need, then the drywall mud calculator for joint compound, tape and screws.
3. Set your budget. Use the drywall installation cost calculator to estimate the total and the cost per square foot, then compare it with contractor quotes.

Drywall basics

Drywall, sheetrock and gypsum board are different names for the same product: a panel of gypsum between two layers of paper. Sheetrock is a brand name that many people use for any drywall.

Sheet size. The most common sheet is 4 by 8 feet, which covers 32 square feet. To estimate sheets, divide the area to cover by 32 and round up. Longer sheets such as 4 by 10 and 4 by 12 feet are also sold. Half-inch board is common on walls, and five-eighths inch board is often used on ceilings and where fire-rated board is needed.

Waste. Cuts, offcuts and mistakes use up board, so most people add an allowance. About 10 percent is a common starting point, and rooms with many corners or openings may need more.

Finish levels. Drywall finish is graded from Level 0 to Level 5 under the Gypsum Association’s GA-214 standard. Level 4 is the usual choice for flat paint, and Level 5 adds a skim coat for a very smooth surface, which costs more.

Other materials. Besides the sheets, a job needs joint compound (also called mud), tape, screws and often corner bead. Coverage differs between products, so check the manufacturer’s label and use the drywall mud calculator to estimate how much compound to buy.

Cost depends on the area, the finish level, ceiling height, your location and local labor rates. Prices change over time, so treat any calculator result as a starting point and get written quotes from local contractors.

Drywall calculator FAQs

Are these drywall calculators free?

Yes. All Calctoolz calculators are free and need no account.

How accurate are the results?

Results are estimates based on standard formulas and the numbers you enter. Measure carefully, and confirm quantities and prices with your supplier or contractor before you buy or hire.

Which calculator should I use first?

Start with the sheetrock calculator to see how many sheets you need. Then use the drywall mud calculator for joint compound, tape and screws, and the installation cost calculator to estimate the budget.

How much extra drywall should I buy?

About 10 percent extra is a common starting point. Rooms with many corners, windows or doors, or an uneven layout, may need more.

Can I calculate the cost for a ceiling only?

Yes. The installation cost calculator lets you choose walls only, ceiling only, or both.

What is the difference between drywall and sheetrock?

There is no difference in the product. Drywall is the general name, and Sheetrock is a brand name that is often used to mean any drywall.

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Planning a bigger project? Explore our other calculator collections.

These calculators give planning estimates only. They do not replace advice from a licensed contractor or inspector. Read our Disclaimer for details.