Drywall Calculator
Calculate drywall sheets, plus screws, joint compound and tape, for walls and ceilings.
What you need
7
Sheets needed — Rounded up, waste allowance included.
- Area to cover
- 200.0 sq ft
- Area including waste allowance
- 220.0 sq ft
- Drywall screws
- 220
- Joint tape needed
- 308.0 ft
- Buckets of joint compound
- 1
About 32 screws per 4x8 sheet at 12 in spacing on 16 in centres.
Roughly 1.4 linear feet of tape per square foot of drywall.
4.5 gallon buckets, allowing three coats over taped seams.
Estimates for planning. Confirm quantities with your supplier before ordering — see the assumptions below for the figures used.
How to use the drywall calculator
Drywall is sold in sheets of a fixed size, so the count is simple area division — but the consumables catch people out. This calculator gives you the sheet count for your chosen size, and estimates screws, tape and mud alongside it.
What this calculator assumes
Every estimate depends on figures that vary by supplier and conditions. These are the ones used here, so you can sanity-check the result against your own quote.
- Coverage per sheet is taken from your entry above — always check the actual packaging, because it varies by product.
- A 10% waste allowance is applied by default. Increase it for diagonal layouts, busy patterns or rooms with lots of corners.
- Sheets are rounded up to whole units.
- Sheet counts are pure area division plus waste. In practice you also want to plan sheet layout to minimise butt joints, which can change the count by a sheet or two.
- Screws are estimated at about one per square foot, which matches 12 inch spacing on 16 inch centres. Buy by the box — a 1 lb box holds roughly 200 screws.
- Joint compound is estimated at one 4.5 gallon bucket per 475 sq ft for three coats over taped seams. Level 5 finishes and skim coats use considerably more.
- Corner bead, fasteners for corners, and primer are not included.
Frequently asked questions
How many sheets of drywall do I need?
Divide your total wall and ceiling area by the sheet size, then add 10%. A room with 416 square feet of wall needs 416 ÷ 32 = 13 standard 4x8 sheets, so 15 with waste. Do not forget the ceiling if you are boarding it.
Should I use 4x8 or 4x12 sheets?
Longer sheets mean far fewer butt joints, which are the hardest seams to hide — so 12 foot sheets give a better finish on a long wall. The catch is weight and handling: a 4x12 half-inch sheet is close to 90 pounds and awkward for one person. If you are working alone, 4x8 is the practical choice.
How much joint compound do I need?
Roughly one 4.5 gallon bucket per 450 to 500 square feet of drywall for a standard three-coat taped finish. All-purpose compound works for every coat; lightweight setting compound is easier to sand but harder to work.
What thickness of drywall should I use?
Half-inch for walls and most ceilings on 16 inch centres. Five-eighths inch for ceilings on 24 inch centres to resist sagging, for fire-rated assemblies such as a garage-to-house wall, and wherever code requires it. Quarter-inch is only for curved surfaces and skim-over work.
How much extra should I buy?
The default here is 10%. Buying a little extra from the same batch is cheap insurance — colours and lots shift between production runs, so a mid-project top-up rarely matches. Keep the offcuts for future repairs.
How do I handle an L-shaped or irregular room?
Split it into rectangles, work out each one separately and add the results. Measure at the widest point of each section and ignore small alcoves unless you are covering them too.
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