Room details
ft
ft
ft
21 sq ft each
15 sq ft each
Sheet size
sq ft
Longer sheets mean fewer butt joints — the hardest seams to finish flat.
%
10% for a simple rectangular room. 15% where there are many corners, soffits, or angled walls.
Drywall Calculator
Sheets, joint compound, tape, and screws for a room. Deducts doors and windows, handles ceilings, and works in 4×8, 4×10, or 4×12.
Buy this much
588 sq ft to cover, plus 10% waste
Get a second pair of hands
Ceiling sheets are the hardest part of any drywall job. A panel lift rents for a day and is worth every cent.
Surface area
- Wall area (gross)
- 416.00 sq ft
- Openings deducted
- −51.00 sq ft
- Ceiling
- +168.00 sq ft
- Total to cover
- 533.00 sq ft
Materials
- Sheets
- 19
- Joint compound
- 82 lb
- Compound buckets
- 2
- Joint tape
- 217 ft
- Screws
- 608
- Screws by weight
- 2.1 lb
Compound assumes a standard three-coat finish. A Level 5 skim coat needs considerably more.
Saved calculations
How this calculator works
Wall area is the room's perimeter × ceiling height, or 2 × (length + width) × height. Openings are deducted at 21 square feet per door and 15 per window. The ceiling, if included, is length × width.
That total is increased by the waste factor and divided by the sheet area, rounded up. Consumables follow standard trade ratios: 0.14 lb of joint compound and 0.37 linear feet of tape per square foot of drywall, and 32 screws per sheet at 16-inch stud spacing.
Buckets assume the standard US 4.5-gallon size at roughly 61 lb, and screw weight assumes about 300 screws per pound for 1¼-inch fasteners.
Worked example
A 14 ft × 12 ft room with 8 ft ceilings, one door, two windows, ceiling included, 4×8 sheets, 10% waste:
- Perimeter: 2 × (14 + 12) = 52 ft
- Gross wall area: 52 × 8 = 416 sq ft
- Openings: 21 + (2 × 15) = 51 sq ft
- Ceiling: 14 × 12 = 168 sq ft
- Total to cover: 416 − 51 + 168 = 533 sq ft
- With 10% waste: 586 sq ft ÷ 32 = 19 sheets
- Compound: 586 × 0.14 = 82 lb, or 2 buckets
Switching to 4×12 sheets drops the count to 13 and cuts the number of butt joints substantially — fewer seams to tape means a flatter finished wall, at the cost of much heavier panels.
What the sheet count doesn't tell you
Hanging drywall is fast. Finishing it is not. Three coats of compound with sanding between each, plus drying time, means a room typically takes several days even when the sheets go up in an afternoon. Budget your time around the finishing, not the hanging.
Also on the list: corner bead for every outside corner, moisture-resistant board for bathrooms and any wall behind tile, and Type X fire-rated board where code requires it — garage ceilings under living space being the common residential case. Half-inch is standard for walls; five-eighths is used on ceilings to resist sagging and wherever fire rating is required.
Common questions
How many sheets of drywall do I need?
Calculate the total wall and ceiling area in square feet, add a waste factor, then divide by the area of one sheet and round up. A 4-by-8 sheet is 32 square feet, a 4-by-10 is 40, and a 4-by-12 is 48. A room with 400 square feet of wall surface needs 440 square feet with 10 percent waste, which is 14 sheets of 4-by-8.
Should I use 4×8, 4×10, or 4×12 sheets?
Longer sheets mean fewer butt joints, and butt joints are the hardest seams to finish invisibly because there is no tapered edge to hide the tape. On an 8-foot wall, a 4-by-12 sheet hung horizontally spans most of a room in one piece. The trade-off is weight and handling — a 4-by-12 half-inch sheet weighs around 70 pounds and is genuinely difficult for one person to manoeuvre.
How much joint compound do I need?
Budget roughly 140 pounds of all-purpose compound per 1,000 square feet of drywall for a standard three-coat finish. That is about two and a half of the 4.5-gallon buckets. Level 5 finishes with a skim coat need considerably more. Buy pre-mixed all-purpose for most jobs — setting-type compound sets chemically and is unforgiving of a slow working pace.
How much drywall tape do I need?
About 370 linear feet per 1,000 square feet of drywall is the standard estimate. Paper tape is stronger and produces flatter joints, but must be bedded in compound correctly or it will bubble. Mesh tape is more forgiving for beginners and self-adhesive, but it is best used with setting-type compound for the first coat because it has less inherent strength.
How many screws per sheet of drywall?
Around 32 screws for a 4-by-8 wall sheet at 16-inch stud spacing, and closer to 36 on ceilings where the fastening pattern is tighter. One pound of 1¼-inch drywall screws contains roughly 300 screws, so a typical room takes a pound or two. Screws should be driven just below the paper surface without tearing it — a dimpler bit is worth the few dollars.
Should I deduct doors and windows?
For estimating sheets, deduct large openings but not small ones. This calculator uses 21 square feet per door and 15 per window. In practice, drywall is often hung straight over an opening and cut out afterwards, which wastes the cutout but produces cleaner edges — so on a room with just one or two openings, many hangers skip the deduction entirely and let it absorb into the waste factor.
Related calculators
- Paint Calculator — gallons with door and window deductions
- Square Footage Calculator — area in sq ft, sq yd, sq m, and acres
- Tile Calculator — tile count, grout, and waste