Drywall Calculator
Sheets = wall plus ceiling area ÷ sheet area, plus waste; screws, compound and tape follow at about 1 lb per 200 ft², 0.053 lb/ft² and 0.4 ft/ft². 640 ft² of board takes 22 sheets of 4 × 8 with 10% waste, 3.2 lb of screws, 34 lb of compound and 256 ft of tape. Sheets only: Drywall Sheet Calculator.
How it's calculated: Sheets = (wall + ceiling area) ÷ sheet area, plus waste; screws ≈ area ÷ 200 lb; compound ≈ area × 0.053 lb; tape ≈ area × 0.4 ft.
Result appears here
Fill in the fields and press Calculate.
Formula, calculation, assumptions and sources
Sheets = (wall + ceiling area) ÷ sheet area, + waste
Screws ≈ 1 lb / 200 ft² · Compound ≈ 0.053 lb/ft² · Tape ≈ 0.4 ft/ft²
Run the calculation to see each step with your own numbers.
A 12 × 16 ft room, 8 ft walls (448 ft²) + 192 ft² ceiling, 4×8 sheets, 10% waste.
Total board = 640 ft²
Sheets = 640 ÷ 32 = 20 → order 22
Screws ≈ 3.2 lb; compound ≈ 34 lb; tape ≈ 256 ft
- Board area is the gross wall + ceiling area; small openings are not deducted (they become cut-offs, covered by waste).
- Screw estimate assumes field + edge fastening at 12–16 in o.c. on wood framing.
- Compound and tape cover taping plus three finish coats to a Level 4 finish. A skim-coat (Level 5) uses more compound.
- Corner bead, adhesive and primer are separate.
- 4×8 or 4×12 sheets?
- 12-ft sheets mean fewer butt joints (the hardest joints to finish invisibly), so pros prefer them on long walls — but they're heavy and awkward in tight spaces. Both give the same total area.
- How much joint compound will I use?
- About 0.05 lb per square foot of board for tape and three coats — roughly one 50 lb box of ready-mix per 900–1,000 ft². A skim-coated (Level 5) finish uses noticeably more.
- Do I deduct doors and windows?
- No. Leaving them in slightly over-counts the board, but the offcuts around an opening are rarely reusable, so it evens out and keeps you from running short.
- How many sheets of drywall for a 12×12 room?
- With 8 ft walls, a 12 × 12 ft room has 384 ft² of wall and 144 ft² of ceiling — 528 ft², or 16.5 sheets of 4 × 8 ft. With the default 10% waste allowance, order 19 sheets.
- How many pounds of drywall screws do I need?
- About 1 lb for every 200 ft² of board, with screws 12–16 in on centre. The 528 ft² of a 12 × 12 ft room with 8 ft walls needs about 2.6 lb; a 1 lb box holds roughly 300 screws.
- How much drywall tape do I need?
- About 0.4 ft of joint tape per square foot of board. A 12 × 12 ft room with 8 ft walls and a ceiling (528 ft²) needs about 211 ft, so one 250 ft or larger roll covers it.
Sheet size
Standard 4×8 ft panel = 32 ft². Nominal panel size (drywall ASTM C1396, plywood/OSB PS 1 / PS 2).
Screw / compound / tape rates
USG 'Drywall Construction Handbook' and CertainTeed estimating tables (≈1 lb screws/200 ft², ≈0.053 lb compound/ft², ≈0.4 ft tape/ft²).
About the Drywall Calculator
The Drywall Calculator estimates everything for a drywall job in one pass — sheets, screws, joint compound and tape — from the wall and ceiling area. Don't deduct small openings; they become the cut-offs the waste allowance covers. Compound and tape cover taping plus three coats to a standard Level 4 finish; a full skim coat uses more. For just the sheet count, use the Drywall Sheet Calculator.
What you enter
- Wall area — Perimeter × ceiling height. Don't deduct small openings.
- Ceiling area
- Sheet size
- Waste allowance — Cut-offs around openings and ends that don't land on a stud. 10–15%.
What you get back
- Drywall sheets — shown as the exact figure and, separately, a recommended figure with your waste allowance added.
- Screws (lb) — ≈ 1 lb of screws per 200 ft² (screws 12–16 in o.c.). A 1 lb box ≈ 300 screws.
- Joint compound (lb) — ≈ 0.053 lb per ft² of board for tape + 3 coats. A ready-mix box is ~50 lb.
- Joint tape (ft) — ≈ 0.4 ft of tape per ft² of board. Rolls are 250–500 ft.
The formula, a worked example, the assumptions behind it and the sources are shown in full below the calculator.
Related calculators
- Drywall Sheet Calculator — Sheet count only for a given wall or ceiling area and sheet size.
- Wall Square Footage Calculator — Wall area for one or more walls, with openings deducted.
- Insulation Calculator — Insulation coverage (batts or bags) for a wall, floor or attic area.
- Paint Calculator — Paint in gallons or litres for a project from surface area and coats.
Related articles
- Drywall vs Drywall Sheet: Understanding Material Quantities — 'Drywall' and 'drywall sheets' usually refer to the same material — the distinction that matters is sheet size and how area converts to a sheet count.
- Plaster vs Drywall: Where Each Is Commonly Used — Plaster and drywall both produce a finished interior wall surface, but they're applied very differently and each remains common in different contexts.
Part of the Drywall & Insulation calculators.