Drywall Calculator
Sheets, joint compound, screws, and tape for a room.
Longer sheets mean fewer joints but are heavy. 4x8 is the DIY standard.
You need
17 sheets
Waste included. Screws assume framing at 16 in on center.
- Surface area
- 477 sq ft
- Joint compound (4.5 gal)
- 2 buckets
- Drywall screws
- 475 screws
- Joint tape (500 ft rolls)
- 1 rolls
Estimates only. Verify quantities before ordering.
How this is calculated
Area = 2 x (length + width) x height, minus 21 sq ft per door and 15 sq ft per window, plus length x width if the ceiling is included. Sheets = area x (1 + waste) / sheet area, rounded up. Compound assumes one 4.5 gallon bucket per 450 sq ft, screws about one per square foot, tape about 37 ft per 100 sq ft.
This calculator takes a room's dimensions, subtracts standard allowances for doors and windows, optionally adds the ceiling, and converts the total into sheet counts for your chosen panel size. It also estimates the finishing materials people forget to buy: joint compound, screws, and tape.
Waste matters more with drywall than with most materials because offcuts around openings, outlets, and odd corners are rarely reusable. 10% is a good default for simple rectangular rooms. Bump it to 15% for rooms with many openings, angled walls, or ceilings that need cutting around fixtures.
Drywall sheets for common rooms
Rows cover walls and ceiling with 8 ft walls, one door, two windows, 4 x 8 sheets, and 10% waste.
| Room size | 4 x 8 sheets | Surface area |
|---|---|---|
| 10 x 10 ft | 13 sheets | 369 sq ft |
| 12 x 10 ft (bedroom) | 15 sheets | 421 sq ft |
| 12 x 12 ft | 17 sheets | 477 sq ft |
| 15 x 12 ft (living room) | 20 sheets | 561 sq ft |
| 24 x 24 ft (2-car garage) | 45 sheets | 1,293 sq ft |
Common questions
What size drywall sheet should I use?
4x8 sheets are the DIY default: light enough to handle and they fit in a pickup. 4x12 sheets produce fewer joints to tape, which is why pros prefer them, but a 12 foot sheet of 1/2 inch drywall weighs over 80 lb and really needs two people or a lift.
How many screws per sheet of drywall?
With studs at 16 inches on center, a 4x8 sheet takes roughly 32 screws: one every 12 inches in the field and every 8 inches on edges is a common pattern, and ceilings get screws slightly closer together. That works out to about one screw per square foot, which is what this calculator uses.
How much joint compound does a room take?
Plan on about one 4.5 gallon bucket of all-purpose compound per 450 to 500 square feet of drywall for a standard three-coat finish. Textured finishes and skim coats use significantly more, so buy an extra bucket if you are texturing.
Do you hang the ceiling or the walls first?
Ceiling first, always. The wall sheets then push up against the ceiling sheets and support their edges, which reduces cracking at the corner joint. Rent a drywall lift for ceilings; it is inexpensive and saves your back and the sheets.