Drywall Calculator
Estimate drywall sheets for a room — walls and ceiling, less doors and windows — plus joint compound, tape, and screws, with U.S. pricing, a sheet-size comparison, and a downloadable PDF.
Finishing quantities are rules of thumb — actual mud, tape, and screw use varies with layout and skill. Prices use 2024-2025 U.S. figures. For planning purposes only.
| Sheet Size | Area | Sheets | Sheet Cost |
|---|
Sheets only, for your 710 sq ft (with waste). Bigger sheets mean fewer seams to tape.
How to use the drywall calculator
Four quick steps turn a room’s dimensions into a full material list — sheets, joint compound, tape, and screws — with U.S. pricing, a sheet-size comparison, and a downloadable PDF.
Enter your room
Type the room length × width, the wall height, and how many identical rooms you’re doing.
Deduct openings
Set the number of doors and windows, and toggle the ceiling on or off.
Pick sheets & finishing
Choose sheet size and thickness, then add compound, tape, screws, and corner bead.
Read it & save a PDF
Get total sheets, finishing materials, and a full cost breakdown to download.
How the sheet count is calculated
Start with the surfaces that get drywall — walls plus the ceiling — subtract the openings, add waste, then divide by the sheet size and round up. Here is the exact math.
Worked example — 16 × 12 ft room, 9 ft walls, ceiling, 1 door + 2 windows
Walls: 2 × (16 + 12) × 9 = 504 sq ft
Ceiling: 16 × 12 = 192 sq ft | Openings: 21 + (2 × 15) = 51 sq ft
Net area: 504 + 192 − 51 = 645 sq ft
With waste: 645 × 1.10 ≈ 710 sq ft
Sheets: ⌈710 ÷ 32⌉ = 23 sheets of 4×8
23 sheets + 2 boxes mud + 2 rolls tape + ~920 screws ≈ $392 in materials, about $0.61 / sq ft.
Drywall coverage & cost charts
Handy lookups for the questions people ask most — sheet sizes and thicknesses, sheets by area, finishing-material rules of thumb, and typical U.S. costs. Everything starts from the drywall area: walls plus ceiling, less openings.
| Sheet Size | Coverage | Best for | ~Price (1/2 in) |
|---|---|---|---|
| 4 × 8 ft | 32 sq ft | Standard rooms, solo work | $14 |
| 4 × 9 ft | 36 sq ft | 9-foot walls | $16 |
| 4 × 10 ft | 40 sq ft | Long walls, fewer seams | $17 |
| 4 × 12 ft | 48 sq ft | Big rooms, flattest finish | $20 |
All sheets are 4 feet wide. Longer sheets cover the same wall with fewer butt joints, cutting down on taping — but they need a helper to hang.
| Thickness | Use | Notes |
|---|---|---|
| 1/4 in | Curves & skim layers | Flexible; bends around radius walls |
| 3/8 in | Remodels & double-layer | Lightweight, easy to handle |
| 1/2 in | Standard walls & ceilings | The default for most rooms |
| 5/8 in Type X | Ceilings, garages, fire-rated | Stiffer; resists sag on 24 in framing |
Use 5/8-inch Type X where fire rating or sag resistance matters; 1/2-inch covers most walls. Always follow local code for fire-rated assemblies.
| Drywall area | With waste | 4×8 sheets | 4×12 sheets |
|---|---|---|---|
| 400 sq ft | 440 | 14 | 10 |
| 600 sq ft | 660 | 21 | 14 |
| 800 sq ft | 880 | 28 | 19 |
| 1,000 sq ft | 1,100 | 35 | 23 |
| 1,200 sq ft | 1,320 | 42 | 28 |
Drywall area is walls plus ceiling, less openings. Divide by the sheet coverage and round up — bigger sheets always land on a smaller count.
| Material | Rule of thumb | Notes |
|---|---|---|
| Joint compound | ~475 sq ft / box | 4.5-gallon box, three coats |
| Joint tape | ~40 ft / sheet | 500 ft roll covers ~12 sheets |
| Drywall screws | ~40 / 4×8 sheet | 320-count box covers ~8 sheets |
| Corner bead | By the 8 ft piece | Outside corners only |
Rules of thumb — actual mud, tape, and screw use varies with layout and finishing skill. Ceilings and fire-rated walls use a tighter screw pattern.
| Component | Typical cost | Notes |
|---|---|---|
| 1/2 in 4×8 sheet | $12–$16 | 5/8 in Type X runs a bit more |
| Joint compound (4.5 gal) | $15–$22 | Ready-mix, per box |
| Joint tape (500 ft roll) | $6–$10 | Paper or mesh |
| Hang & finish labor | $40–$70 / sheet | Hang, tape, and finish |
Planning ranges only. Prices swing with region and quantity — a full pallet is cheaper per sheet than a handful from the store.
Drywall covers the walls and the ceiling. Add the wall area (perimeter × height) to the ceiling area, then subtract the doors and windows you won’t be sheeting over.
- Walls — 2 × (length + width) × the ceiling height.
- Ceiling — length × width, added when you’re sheeting it too.
- Openings — subtract ~21 sq ft per door and ~15 per window.
Everything the calculator works out
One room, entered any way you like, comes back as a complete material list — sheets and every finishing item, priced out.
Key figures behind drywall estimating
Built for anyone hanging drywall
From a single basement room to a whole-house rock job, the same calculator turns dimensions into sheets, mud, and a materials price.
Finishing a basement, garage, or spare room and needs the sheet, mud, and screw count.
- Enter the room, get sheets
- Toggle the ceiling on or off
- Add a spare sheet for mis-cuts
Turning room dimensions into sheets, finishing materials, and a price fast when quoting work.
- Multiply identical rooms at once
- Compare sheet sizes by seams
- Add labor per sheet for a bid
Weighing sheet sizes and materials against labor before booking a drywall job.
- See cost per square foot
- Split materials from labor
- Save the PDF to shop quotes
7 tips for estimating & hanging drywall
Small habits keep your sheet and mud counts right, whether you’re rocking one room or a whole floor.
Drywall calculator FAQ
The coverage, sheet, finishing, and cost questions people ask most.
Add up the wall and ceiling area, subtract the doors and windows, then divide by the sheet size. Walls are the perimeter times the ceiling height — 2 times (length plus width) times height — and the ceiling adds length times width.
For a 16 by 12 foot room with 9-foot walls and a ceiling, that works out to about 645 square feet, or roughly 23 sheets of 4×8 drywall once you add about 10% for waste.
Sheets are 4 feet wide in 8, 9, 10, and 12-foot lengths. A 4×8 sheet covers 32 square feet and is the easiest to carry and hang solo.
Longer sheets like 4×12 cover the same wall with fewer seams, which means less taping and a flatter finish, but they’re heavy and awkward without a helper. Match the sheet length to your wall runs to cut down on butt joints.
Plan on roughly one 4.5-gallon box of ready-mix compound per 475 square feet of drywall across three coats, so a typical room takes one to two boxes.
Actual use depends on how many seams you have and your finishing skill, and bigger sheets mean fewer joints and a little less mud. Buy a bit extra — it’s cheap, and you don’t want to run out partway through a coat.
Figure about 40 screws per 4×8 sheet — roughly the standard spacing of every 16 inches in the field and 8 inches along the edges on walls.
Ceilings and fire-rated assemblies use a tighter pattern and more screws. A box of about 320 screws covers roughly eight sheets, so a small room usually needs two or three boxes.
Half-inch is the standard for most walls and ceilings. Use 5/8-inch Type X for ceilings, garages, and any fire-rated wall — it’s stiffer and resists sagging on 24-inch framing.
Quarter-inch is for curved walls and skimming over old surfaces, and 3/8-inch is a lightweight choice for remodels and double-layer work. Always check local code for fire-rated locations.
Estimate about 40 linear feet of tape per 4×8 sheet to cover the flat joints and inside corners. A 500-foot roll then handles roughly a dozen sheets.
Paper tape is strong and cheap for flat seams and corners, while self-adhesive mesh is easier for beginners on flat butt joints. Round up to whole rolls and keep a spare on hand.
Yes, but keep it simple. Deduct roughly 21 square feet for a standard door and about 15 square feet for an average window from your wall area.
Many pros only subtract large openings and leave small ones in as built-in waste, since you still cut drywall around them. Subtracting keeps the sheet count honest on rooms with lots of glass or several doorways.
Materials — sheets, compound, tape, and screws — typically run about $0.50 to $0.90 per square foot of drywall, so a 645 square foot room is roughly $350 to $550.
Professional hang-and-finish labor adds about $40 to $70 per sheet. Sheet size, thickness, ceiling height, and how many corners and openings you have all move the final number.
General Estimating Notice: This calculator estimates drywall sheets, joint compound, tape, screws, and corner bead from your room dimensions and sheet choice, using standard coverage figures. Openings are deducted at about 21 square feet per door and 15 per window, and finishing quantities are rules of thumb — actual mud, tape, and screw use varies with layout, sheet size, and finishing skill. Prices use 2024–2025 U.S. figures and exclude fasteners for framing, primer, paint, and specialty boards. Follow the manufacturer’s fastening pattern and local building code, and use fire-rated board where required. For planning purposes only.