Drywall Calculator
Sheets, compound, screws & tape
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Formula & explanation
Wall area is the perimeter times ceiling height. Add the ceiling area (length × width) if you're boarding it too. Divide by the sheet's area (4×8 = 32 sq ft) and round up, after applying the waste allowance for cuts and damage.
Example calculation
12 × 14 ft room, 8 ft walls, with ceiling, 4×8 sheets, 10% waste:
Walls = 2×26×8 = 416 sq ft. Ceiling = 168 sq ft. Total = 584 × 1.10 = 642 sq ft ÷ 32 = 20.1 → 21 sheets, ~17 lb of screws.
Buying & project-planning tips
- 4×8 sheets are DIY-friendly and fit in most pickups; 4×12 sheets halve ceiling seams but need two installers.
- Use 1/2" drywall for walls, 5/8" fire-code for garages and shared walls per code.
- Leave a small gap at the floor — drywall shouldn't touch the subfloor.
- Countersink screws slightly without breaking the paper for a smooth mud finish.
- Order corner beads separately — L-corner or paper-faced beads aren't included in sheet counts.
Frequently asked questions
What thickness drywall do I need?+
1/2" for most walls, 5/8" for fire-rated assemblies and ceilings with 24" joist spacing, 1/4" or 3/8" only for curved surfaces or repairs.
How much joint compound and tape?+
A 5-gallon bucket of all-purpose compound covers roughly 200 sq ft of finished wall. A 500-ft roll of tape covers about 380 sq ft of joints.
4×8 or 4×12 sheets?+
4×8 sheets are easiest for one person and fit in a pickup. 4×12 sheets reduce seams (fewer joints to mud) but require two installers and a bigger vehicle.
Do I need green board in bathrooms?+
Moisture-resistant drywall (green board) is recommended behind tile in wet areas, but cement board is required in steam showers per most codes.