Drywall calculator
Covers walls and, optionally, the ceiling of one rectangular room. Compound and tape use planning rates per 1,000 sq ft that you can change to match the product you buy.
Materials takeoff
Drywall Calculator · https://estimahome.com/drywall-calculator/
Room length: 12 ftRoom width: 12 ftWall height: 8 ftHang the ceiling: YesDoors: 1 eaWindows: 1 ea
- Wall area
- 348 sq ft
- Ceiling
- 144 sq ft
- Total area
- 492 sq ft
- Compound
- 4.6 gal
| No. | Item | Qty | Unit | Unit cost | Amount |
|---|---|---|---|---|---|
| 1 | Drywall, 4 × 8 ft, 1/2 in | 17 | sheet | $16.00 | $272.00 |
| 2 | Joint compound, 4.5 gal | 2 | ea | $20.00 | $40.00 |
| 3 | Paper tape, 250 ft | 1 | roll | $5.00 | $5.00 |
| 4 | Drywall screws (544 pcs) | 1 | box | $22.00 | $22.00 |
- Subtotal
- $339.00
- Likely range
- $288.15 – $389.85
- Ceilings and walls over 8 ft often go faster with 4 × 12 sheets (fewer seams).
- Not included: corner bead, sanding supplies, moisture-resistant board for wet areas.
Buy these materials
- 17 4 × 8 drywall sheetsAmazon search for 4 × 8 drywall sheets (opens in new tab)
- 2 buckets of joint compoundAmazon search for buckets of joint compound (opens in new tab)
- 1 roll of drywall tapeAmazon search for rolls of drywall tape (opens in new tab)
- 1 box of drywall screwsAmazon search for boxes of drywall screws (opens in new tab)
Links open a store search for each item. Check sizes and grades against your plan.
Quick reference
- A 12 × 12 ft room with 8 ft walls and a ceiling needs about 17 sheets of 4 × 8 drywall with 10% waste.
- A 4 × 8 sheet covers 32 sq ft; a 4 × 12 covers 48 sq ft.
- Sheets = wall and ceiling area × (1 + waste) ÷ sheet area, rounded up.
How it's calculated
⌈x⌉ means round up to the next whole unit; ⌊x⌋ means round down. Every quantity you buy is rounded up.
Wall area = 2 × (length + width) × height − doors × door area − windows × window areaTotal area = wall area + ceiling (length × width, if hung)Sheets = ⌈ total area × (1 + waste ÷ 100) ÷ sheet area ⌉Compound buckets = ⌈ total area ÷ 1,000 × compound rate ÷ bucket size ⌉Tape rolls = ⌈ total area ÷ 1,000 × tape rate ÷ roll length ⌉Screws = sheets × screws per sheet × (sheet area ÷ 32); boxes = ⌈ screws ÷ per box ⌉Cost = Σ (quantity × unit price); range = cost × (1 ± range % ÷ 100)
Worked example
A 12 × 12 ft room with 8 ft walls has 384 sq ft of wall; less one door and one window that is 348 sq ft. Adding the 144 sq ft ceiling gives 492 sq ft. With 10% waste, 492 × 1.1 ÷ 32 = 17 sheets of 4 × 8. At 9.4 gal per 1,000 sq ft the job takes 4.62 gal of compound, 2 buckets. Tape is 182 ft, 1 rolls. 32 screws per sheet is 544 screws. Materials at the default prices: $339.00.
Questions
Should I subtract doors and windows?
For a closer count, yes. Many hangers subtract only large openings, since the cutouts from small windows are rarely reusable. The default subtracts both and adds 10% waste.
4 × 8 or 4 × 12 sheets?
4 × 12 sheets mean fewer butt joints to tape, but they are heavy and need two people. 4 × 8 is easier to carry and better for small rooms and ceilings you are hanging alone.
How many screws per sheet of drywall?
About 32 for a 4 × 8 sheet on walls at 16 in on center, more on ceilings. Check your local code for spacing.
How much joint compound per sheet?
Roughly 1 gal for every 3 to 4 sheets over three coats. A 4.5 gal bucket finishes about 15 sheets.
Cite: “Drywall Calculator.” EstimaHome, https://estimahome.com/drywall-calculator/. Updated 2026-10-20. Formulas in machine-readable form: /api/calculators.json.