Drywall Calculator
Estimate the drywall sheets, joint compound, tape, and screws to finish a room from your wall and ceiling square footage. Choose 4×8 or 4×12 panels and add a waste factor so you buy enough to hang and tape in one go.
How to Use
- Enter the total wall area in square feet — add up each wall (length × height) for the room.
- Enter the ceiling area in square feet, or leave it at zero if you are only hanging walls.
- Pick the sheet size: 4×8 panels (32 ft²) are easier to handle, 4×12 panels (48 ft²) mean fewer seams.
- Set a waste percentage (10% is typical) to cover cuts around openings, corners, and damaged sheets.
- Read the sheet count plus the mud, tape, and screw estimates, and check the step-by-step Show Work below.
Show Work
Coverage
About the Drywall Calculator
Meet the Drywall Calculator: a free, no-fuss tool for building, materials estimation and site work with nothing to install and no sign-up. Estimate the drywall sheets, joint compound, tape, and screws to finish a room from your wall and ceiling square footage. Choose 4×8 or 4×12 panels and add a waste factor so you buy enough to hang and tape in one go.
How it works
Put each value in its box and read the answer as you go. Because it recalculates live, you can play with the inputs to see how each one moves the result — handy for checking your own working or planning ahead. Everything happens on your device, so it is fast and private.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How many drywall sheets do I need?
Divide your total wall and ceiling area by the coverage of one sheet — 32 square feet for a 4×8 or 48 for a 4×12 — then add waste. The tool does this for you. For a rough feel, a 12 by 12 room with 8 ft walls and a ceiling needs roughly 16 to 18 sheets of 4×8 once waste is included.
Should I use 4×8 or 4×12 sheets?
Bigger 4×12 sheets cover more wall with fewer butt joints, which means less taping and a flatter wall — pros prefer them on long, tall walls. But they are heavy and awkward to carry through doorways and up stairs. For DIY work in tight rooms, 4×8 sheets are far easier to handle even though you tape more seams.
How much joint compound and tape will I need?
A good rule is about one gallon of mud per 100 square feet of drywall across all coats, and roughly one linear foot of tape for every square foot of board. The tool estimates both. Buy a little extra mud — it is cheap, and running out between coats while the first batch sets up is a real annoyance.
How many screws per sheet?
Figure about 32 screws per sheet: roughly every 8 inches along the edges and every 12 inches in the field for walls. Ceilings get more, since gravity is working against you. The tool scales the screw count to your sheets, so just buy by the box and keep a cushion on hand.
Do I subtract doors and windows?
For a quick estimate you usually do not, and the leftover around openings becomes part of your waste cushion. If a room has very large openings — a big picture window or a wide cased opening — knock that area off your wall total so you do not badly over-order. Otherwise the standard 10% waste covers it.
How do I use the Drywall Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Do I need to install or sign up for anything?
Not at all — it runs in the browser with nothing to install and no account. After it loads once, it even works without an internet connection.
Is my information private?
Yes. Everything happens in your browser. Nothing you type is sent to a server or saved anywhere.
Common Use Cases
Hanging a new room
Turn wall and ceiling square footage into a sheet count so you order the right number of panels in one delivery.
Finishing a basement or garage
Estimate sheets for walls-only jobs where the ceiling is left open or done separately.
Stocking mud and tape
Get joint compound and tape quantities so you have enough on hand for every coat without a mid-job supply run.
Comparing panel sizes
See how 4×8 versus 4×12 sheets change your count and seam work before you pick what to haul home.
Budgeting a remodel
Price the board, mud, tape, and screws up front to fit drywall into the overall job estimate.
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