Drywall Estimator — Sheets, compound & tape
All the materials needed for any drywall job — number of sheets, bags of joint compound, rolls of tape and box of screws. Includes door / window deductions and 10% wastage.
Quick answer
For a 12×12 ft room with 9 ft ceiling: ~20 sheets of 4×8 ft drywall, 6 gallons of joint compound, 1–2 rolls of tape and 1 box of screws (1¼"). Always order 10% extra sheets.
Room details
Materials needed
20sheets
4×8 ft drywall for 12×12 ft room
Wall area432 sqft
Ceiling area144 sqft
Door / window deduction-36 sqft
Total drywall area540 sqft
Drywall sheets19 sheets
Joint compound6 gallons (~27 kg)
Drywall tape2 rolls × 250 ft
Screws (1¼")1 box (~270 screws)
Estimated cost₹13,000
How drywall materials are calculated
Drywall (gypsum board, sheetrock) requires four materials in addition to the panels themselves: joint compound (mud) for taping seams, paper or fibre tape, drywall screws, and corner bead at outside corners. The calculator gives you all five quantities for any room.
Drywall area: walls + ceiling − doors − windows.
Sheets: ⌈area × 1.10 ÷ sheet area⌉.
Joint compound: ~1 gallon per 100 sqft.
Tape: 1 roll per 400–500 sqft.
Sheets: ⌈area × 1.10 ÷ sheet area⌉.
Joint compound: ~1 gallon per 100 sqft.
Tape: 1 roll per 400–500 sqft.
Material coverage rates
| Material | Coverage | Notes |
|---|---|---|
| 4×8 ft sheet | 32 sqft | Standard size for residential |
| 4×10 ft sheet | 40 sqft | For taller walls (10 ft+) |
| 4×12 ft sheet | 48 sqft | For commercial / faster install |
| Joint compound (1 gallon / 4.5 kg) | 100 sqft | 2 coats over taped seams |
| Tape (250 ft roll) | 400–500 sqft | Paper or fibre mesh |
| Screws (1¼", box of 1 lb) | 500 sqft | ~32 screws per 4×8 sheet |
Drywall thickness guide
- 1/2" (12.5 mm) — most common, walls and ceilings in residential
- 5/8" (15 mm) — for ceilings (sags less), fire-rated walls, sound-rated walls
- 3/8" (10 mm) — for repairs over existing surfaces, curved walls
- 1/4" (6 mm) — for layering / curved shapes only
Tips for ordering
- Always order 10% extra sheets — for cuts, breakage and on-site changes.
- Order 1 extra bag of compound — finishing always takes more than expected.
- Use 1¼" screws for 1/2" drywall on wood studs, 1⅝" for 5/8" drywall.
- Get corner bead separately — 1 piece per outside corner, in 8 ft or 10 ft lengths.
Frequently asked questions
How many drywall sheets for a 12x12 room?
A 12×12 ft room with 9 ft ceiling has about 432 sqft of wall + 144 sqft of ceiling = 576 sqft. Using 4×8 ft (32 sqft) sheets, you need 18 sheets + 10% waste = ~20 sheets. For 4×12 ft sheets (48 sqft), you need 13 sheets.
How much joint compound for drywall?
Standard rule: 1 gallon (4.5 kg) of joint compound per 100 sqft of drywall. A 12×12 room with ~576 sqft of drywall needs about 6 gallons (27 kg) of compound, plus a 5 kg bag for finish coat.
How much drywall tape do I need?
1 roll of 250 ft drywall tape covers about 400–500 sqft of drywall. A 12×12 ft room needs roughly 1–2 rolls. Always buy 1 spare roll for repairs.
What screw size for drywall?
1¼" coarse-thread screws for 1/2" drywall on wood studs. 1⅝" for 5/8" drywall. Use fine-thread screws on metal studs. Plan for ~32 screws per 4×8 ft sheet.
Should I include the ceiling in my drywall estimate?
If you're drywalling the ceiling too, yes — add the ceiling area (length × width). Ceilings need slightly thicker drywall (5/8" preferred over 1/2") because they sag with gravity over time.
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