Drywall Calculator
Enter your room dimensions to calculate the number of drywall sheets, boxes of screws, rolls of joint tape, and buckets of compound needed for your project.
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Sheets of drywall
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ft² (with waste)
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Boxes of screws
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Rolls of tape (75 ft)
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Buckets of compound (5 gal)
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Net wall area (ft²)
Estimates include 10% waste for sheets. One box of drywall screws covers ~500 ft². One 75-ft roll of tape covers approximately 10 sheets. One 5-gal bucket of all-purpose compound covers approximately 400 ft².
How to Calculate Drywall
Add up the total wall area (perimeter × ceiling height), subtract doors and windows, then add the ceiling area if applicable. Divide by the sheet area and add 10% waste to get the sheet count.
Drywall Thickness Guide
| Thickness | Use |
|---|---|
| ¼ inch (6 mm) | Curved walls, covering old panelling |
| 3/8 inch (10 mm) | Repairs; rarely used for new work |
| ½ inch (13 mm) | Standard for walls and ceilings on 16" O.C. framing |
| 5/8 inch (16 mm) | Ceilings with 24" O.C. framing; fire-rated assemblies (Type X) |
Use ½-inch for most wall and ceiling applications. Use 5/8-inch Type X drywall for garage walls and ceilings that attach to living space — required by most building codes for fire separation.
Joint Finishing Levels
Drywall finishing is rated in levels 0–5 by the Gypsum Association:
| Level | Description | Typical use |
|---|---|---|
| 0 | No tape, no finish | Temporary construction |
| 1 | Tape embedded, no compound | Concealed areas (attics) |
| 2 | Tape + one coat compound | Tile backer, garages |
| 3 | Tape + two coats | Textured finish |
| 4 | Tape + three coats | Flat paint, light texture |
| 5 | Level 4 + skim coat | Gloss or semi-gloss paint |
Most residential rooms are finished to Level 4. A Level 5 skim coat is recommended before gloss paint or strong side-lighting that would highlight surface imperfections.
Taping vs. Topping Compound
- All-purpose compound (mud) — used for embedding tape and all three coats; widely available; slower drying
- Taping compound — harder and more crack-resistant; best for the tape-embed coat
- Topping compound — lighter and smoother; best for final finish coats; easier to sand
- Setting-type (hot mud) — powder that sets by chemical reaction (not drying); much faster; great for large gaps and first coat; cannot be re-wetted
- Pre-mixed — ready to use out of the bucket; most common for DIY
Frequently Asked Questions
How many sheets of drywall do I need for a 12×12 room?
A 12×12 room with 8-foot ceilings has a wall perimeter of 48 linear feet. Wall area = 48 × 8 = 384 ft². Subtract 1 door (21 ft²) and 2 windows (30 ft²) = 333 ft² of walls, plus 144 ft² ceiling = 477 ft². With 10% waste and 4×8 sheets (32 ft² each): approximately 17 sheets of drywall.
Can I hang drywall by myself?
Walls can be hung solo with the right tools (a drywall lift or simple props to hold the bottom edge). Ceilings are significantly harder and are best tackled with at least one helper, or a rental drywall lift.
Should I use screws or nails for drywall?
Screws are strongly preferred. Nails can pop over time as framing dries and moves. Use coarse-thread drywall screws for wood framing and fine-thread screws for metal studs. Space screws every 12 inches in the field and every 8 inches at edges and butt joints.
