YardMath

Drywall calculator

Form 44 · Materials estimateFigures checked 2026-09-04
US customary
Quantity · Amount
  1. 01Wall area2 × (12 + 14) × 8 ft416 sq ft
  2. 02Ceiling area168 sq ft
  3. 03Sheets of 32 sq ft642 sq ft with 10 % waste at $16 each21 sheets$336
  4. 04Joint compound, 4.5 gal bucketsabout one bucket per 20 sheets2 buckets$36
  5. 05Joint tape, 250 ft rollsabout 40 ft of joint per sheet4 rolls
  6. 06Screws, 1 lb boxes (≈320)32 screws per sheet3 boxes
Total, board and mud$372
  • Longer sheets mean fewer butt joints to finish; use 12 ft board where you can carry it in.
  • Ceilings take ⅝ in board on 24 in framing to stop sagging.
Include the ceiling
Total, board and mud21 sheets$372
Where these figures come from
  • Sheet sizes 4 × 8, 4 × 10, 4 × 12 ft and the per-sheet mud, tape and screw rates: standard US drywall estimating figures.
  • Prices are typical US retail figures at the date on this sheet.

Type the room and choose the sheet size (4 × 8, 4 × 10 or 4 × 12). The sheet counts boards for the walls and ceiling with a 10 % allowance, then adds joint compound, tape and screws at the usual per-sheet rates.

Worked examples

Bedroom 12 × 14 ft, 8 ft walls and ceiling
21 sheets — sheets of 32 sq ft, about $372 in board and mud.
Garage 24 × 24 ft, 9 ft walls, no ceiling
30 sheets — sheets of 32 sq ft, about $516 in board and mud.

How it is worked out

Area = walls (2 × (L + W) × H) + ceiling (L × W), × rooms, × (1 + waste). Sheets = area ÷ the sheet's square feet, rounded up. Mud = sheets ÷ 20 buckets. Tape = sheets × 40 ft ÷ 250. Screws = sheets × 32 ÷ 320 per pound.

The figures behind it

  • Sheet sizes 4 × 8, 4 × 10, 4 × 12 ft and the per-sheet mud, tape and screw rates: standard US drywall estimating figures.
  • Prices are typical US retail figures at the date on this sheet.

Every figure here is an estimate. Materials vary with moisture, compaction and product; order a little extra and confirm quantities with your supplier.

Questions people ask

How many sheets of drywall do I need?
Total wall and ceiling area plus 10 % divided by the sheet's square feet: 32 for 4 × 8, 40 for 4 × 10, 48 for 4 × 12. A 12 × 14 ft room with an 8 ft ceiling needs about 21 sheets of 4 × 8.
How much joint compound per sheet?
About one 4.5 gallon bucket per 20 sheets for a three-coat finish, more for a level-5 skim. Tape runs roughly 40 ft per sheet.
Do I subtract doors and windows?
Most estimators do not for drywall: the offcuts rarely fit anywhere else, so the openings pay for the waste. This sheet uses the full area plus your allowance.

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