Quantity · Drywall
Drywall Calculator
Size a rectangular room in drywall sheets from length, width, and height. Subtract doors and windows, pick 4×8 / 4×10 / 4×12, and get screws, joint compound, and tape with the sheet count. Waste defaults to 10%.
Room dimensions
Most common residential sheet.
Sheets to buy
17sheets
488 sq ft net · 4' × 8' (32 sq ft)
- Walls
- 384 sq ft
- Ceiling
- 144 sq ft
- Screws
- ~544
- Joint compound
- ~5 gal
- Tape
- ~196 lf
- Installed band
- $732–$1,708
Raw 15.3 sheets → with 10% waste. Installed range is hang + finish national average — not a bid. Texture, corners, and scaffolding are separate.
- Walls = 2 × (L + W) × H; optional + ceiling
- Net = gross − openings; × layers if double board
- Sheets = ceil(net ÷ 32 × (1 + 10%))
Price data updated . National US ranges from published supplier and contractor averages. Not a bid. Local quotes vary.
How drywall quantity is calculated
Wall area is the perimeter times height. Ceiling is optional length × width. Openings come out before you divide by sheet coverage. Accessories scale from the finished board area using standard field rates.
walls = 2 × (length + width) × height ceiling = length × width (optional) net_area = walls + ceiling − openings finish_area = net_area × layers sheets_buy = ceil(finish_area / sheet_sq_ft × (1 + waste %)) screws ≈ sheets × 32 mud_gallons ≈ ceil(finish_area / 100) tape_lf ≈ ceil(finish_area / 1000 × 400)
Worked example. A 12 × 12 × 8 ft room with ceiling and 40 sq ft of openings: walls 384 + ceiling 144 = 528 gross → 488 net. At 4×8 (32 sq ft) and 10% waste → ceil(488/32 × 1.10) = 17 sheets. Screws ~544, mud ~5 gal, tape ~196 lf. Installed hang+finish often lands near $730–$1,700 for that net area.
Drywall accessories per finished area
These field rates are what most DIY calculators skip — and why sheet-only estimates leave you short at the store. Confirm on product labels for your mud and tape brand.
| Item | Planning rate | Unit | Notes |
|---|---|---|---|
| Drywall screws | 32 | per sheet | Field hang rate; corners may need more |
| Joint compound | 1 | gal / 100 sq ft | All coats planning average |
| Joint tape | 400 | lf / 1,000 sq ft | Paper or mesh — buy a roll extra |
| Waste | 10% | of sheets | Cuts, damage, odd walls |
- Corner bead, primer, and texture are not included in these rates.
- Installed $/sq ft band on the result is hang + finish national average.
Sheet coverage (before waste)
Divide net finish area by coverage, then add waste and round up.
| Sheet | Sq ft each | Sheets / 500 sq ft* | Best for |
|---|---|---|---|
| 4 × 8 | 32 | 16 | Standard rooms, DIY lifts |
| 4 × 10 | 40 | 13 | 9–10 ft walls, fewer seams |
| 4 × 12 | 48 | 11 | Long walls; two-person hang |
- *Before waste — multiply by 1.10 and round up.
- Thickness (1/2", 5/8" Type X) does not change sheet count.
Drywall calculator FAQ
- How many sheets of drywall do I need?
- Add wall and ceiling area, subtract openings, divide by the sheet size (32 / 40 / 48 sq ft), multiply by (1 + waste %), and round up. This calculator does that and adds screws, mud, and tape.
- Should I subtract doors and windows?
- Yes. Measure each opening (width × height) and enter the total. Skipping openings over-orders sheets and mud.
- How much joint compound do I need?
- A common planning figure is about 1 gallon per 100 square feet of finished board for all coats. Texture and heavy fills take more.
- 4×8 or 4×12 sheets?
- 4×8 is easiest to carry and hang alone. Longer sheets mean fewer seams on tall or long walls but need two people and a bigger vehicle.
- Does the installed dollar range include hanging and finishing?
- Yes — it is a national hang + finish band ($1.50–$3.50/sq ft). Texture, scaffolding, and demolition are separate.
- What about Type X or moisture-resistant board?
- Sheet count is the same; only the product changes. Use Type X where code requires fire rating, and moisture-resistant in baths (not a tile backer substitute).
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