Drywall Calculator
By Stephen Morrison, Editor Last reviewed
Enter your room and get the number of drywall sheets for the walls and ceiling, plus how much joint compound and tape to finish them.
Quick answer: a 12 × 12 ft room with 8 ft walls, one door, two windows and the ceiling takes 17 sheets of 4 × 8 drywall(12 walls + 5 ceiling, 10% extra included), about 1 pail of joint compound and 177 ft of tape.
How the calculator works
Ceiling: length × width
Sheets: area × (1 + waste%) ÷ sheet area, rounded up (walls and ceiling separately)
Compound: 2 × 4.5 gal pails per 1,000 sq ft of board
Tape: 370 ft per 1,000 sq ft of board
Walls and ceilings are counted separately because ceilings are often hung with a different board, such as a sag-resistant ceiling panel.
Sheets for common rooms
8 ft walls, one door, two windows, ceiling included, 10% extra.
| Room | Board area | 4 × 8 sheets | Compound pails |
|---|---|---|---|
| 10 × 10 ft | 370 sq ft | 14 | 1 |
| 12 × 12 ft | 478 sq ft | 17 | 1 |
| 12 × 14 ft | 534 sq ft | 19 | 2 |
| 14 × 16 ft | 654 sq ft | 23 | 2 |
| 16 × 20 ft | 846 sq ft | 30 | 2 |
Sheet sizes
| Sheet | Area | Best for |
|---|---|---|
| 4 × 8 ft | 32 sq ft | DIY, small rooms, fits most vehicles |
| 4 × 10 ft | 40 sq ft | Hanging horizontally on 9–10 ft walls |
| 4 × 12 ft | 48 sq ft | Fewer seams on long walls and ceilings; needs two people |
Common questions
How many sheets of drywall for a 12 × 12 room?
With 8 ft walls, one door, two windows and the ceiling, it's 478 sq ft of board. With 10% extra that's 17 sheets of 4 × 8: 12 for the walls and 5 for the ceiling.
How much joint compound do I need?
USG estimates about 2 pails of 4.5 gallons of its lightweight all-purpose compound per 1,000 sq ft of drywall, and says its other ready-mix compounds are similar. The 478 sq ft room above needs about 4.3 gallons, so buy 1 pail.
How much drywall tape do I need?
About 370 ft of paper tape per 1,000 sq ft of board, per USG. A 500 ft roll covers roughly 1,351 sq ft of board.
Should I use 4×8 or 4×12 sheets?
Longer sheets mean fewer seams to tape and sand, which saves finishing time. But 4×12 sheets weigh more, are harder to get through doors and up stairs, and usually need two people. 4×8 sheets fit in more vehicles.
Should I subtract doors and windows?
This calculator does (20 sq ft per door and 15 sq ft per window), then adds 10% back for cuts. Openings are rarely clean savings, because the board around them is cut from full sheets. For a room with many openings, raise the waste figure.
How many screws do I need?
It depends on framing spacing, board thickness and your local code, so we don't guess a number. Follow the fastener spacing in the board maker's instructions and buy a box sized for the sheet count.
Sources
- USG FAQ: about two 4.5-gallon pails of Sheetrock UltraLightweight All Purpose compound per 1,000 sq ft
- USG submittal sheet, Sheetrock Brand Heavy Joint Tape (hosted by Home Depot): approx. 370 ft per 1,000 sq ft of gypsum panels
Formulas and figures last checked against these sources on. Spotted an error? Tell us and we'll fix it.
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