Drywall calculator
Rooms are not neat multiples of 32 square feet. You need a sheet count you can load in the truck, plus enough joint compound and screws so you are not mid-tape with an empty bucket. Enter wall and ceiling areas (or room dimensions), pick sheet size, set waste, and read sheets plus supply rules of thumb. This page does not hang board for you or price labor.
+10% so you don't come up short
Estimate only — not a contractor bid. Confirm bag yields and local codes before you pour or order.
When to use
Basement finish shopping list; one-room remodel; checking a supplier quote against your tape measure.
When not to
Curved walls, archways, or commercial UL assemblies — those need a takeoff. Moisture-prone baths may need special board types this page does not specify.
Assumptions
Default sheet 4×8 ft = 32 sq ft. Waste default 10%. Mud / tape / screws are approximate DIY rates (e.g. ~1 gal mud per 100 sq ft finish rough cut; tape ≈ perimeter of sheets; screws ≈ 1 per sq ft of board) — brand coverage wins.
Worked examples
Example 1
12×12 room, 8 ft walls, no ceiling board, waste 10%, ignore two doors (~40 sq ft)
→ wall area ≈ 344 sq ft → with waste ≈ 378 → 12 sheets of 4×8
Layout (horizontal vs vertical) can save a sheet — the math is a buy count, not a hang plan.
Example 2
10×14 ceiling only, waste 10%
→ 140 × 1.1 = 154 → 5 sheets
Ceilings hate seams in the middle of the room — buy the count, then plan joints.
How it calculates
Net area from room dims or entered square footage, divide by sheet size with waste, then rough supply lines.
- Enter length, width, and ceiling height — or paste a net area.
- Subtract doors/windows; optionally include the ceiling.
- Set sheet size and waste; read sheets, mud, tape, and screws.
net area = walls + ceilings − large openings sheets = ceil(net area × (1 + waste%) ÷ sheet_area) supplies from area × rule-of-thumb rates (approximate)
Common traps
- Openings — forgetting doors/windows over-orders; counting every outlet as a void under-orders.
- Sheet size — 4×10 or 4×12 changes the ceil math; set the field to what the aisle stocks.
- Butt joints and texture burn mud faster than smooth remodels.
- Greenboard / moldboard is a product choice, not a different area formula.
Next tool
After board, paint gallons → paint calculator.
Tile over cement board is a different stack — see tile calculator.
FAQ
Wall (+ ceiling) area ÷ 32 for 4×8, add waste, round up.
Related
Estimate only — not a contractor bid or engineered takeoff. Confirm bag yields and local codes before you pour or order.