Sheet planning made practical
Drywall Calculator
Plan drywall for multiple rooms, walls, and ceilings, then build an itemized order for sheets and finishing supplies.
How to estimate drywall sheets for rooms and ceilings
- Add each room in four-wall mode, entering room length, width, and height. For individual walls, use single-wall mode and enter length and height.
- Add each flat ceiling as a separate ceiling rectangle. Split irregular surfaces into rectangles.
- Deduct the total area of doors and windows once, then set a cutting allowance for each surface.
- Choose wall and ceiling sheet sizes, prices, and product weights. All surfaces in each group share one board product.
- Add finishing supplies, tax, and review the shopping list. Export CSV or print a copy.
The calculator saves your latest valid project in this browser when storage is available. It supports up to 50 room or surface entries. Prices are in USD and start at zero.
Drywall area and sheet formulas
Single wall or ceiling area = length × height or width
Net area = gross area − openings
Order area = net area × (1 + waste ÷ 100)
Sheets = round up(combined product order area ÷ sheet area)
Board weight = purchased sheets × weight per sheet
A 4 × 8 sheet covers 32 square feet; a 4 × 12 sheet covers 48 square feet. Wall and ceiling groups round independently, even if their board sizes match. Supply coverage uses net area and its own allowance, rather than the sheet cutting allowance.
Example: a 12 × 10 foot bedroom
At 8 feet high, four walls have 352 square feet of gross area. Deducting 32 square feet of openings leaves 320. A 10% allowance gives 352 square feet, requiring 11 sheets of 4 × 8 wall board.
The 120-square-foot ceiling needs 132 square feet with the same allowance, or 5 sheets of 4 × 8 ceiling board. At $15 per wall sheet, $16 per ceiling sheet, and two $20 compound containers, the subtotal is $285. With 8% tax, the example total is $307.80. These prices and supply quantities are illustrative.
Drywall planning questions
Does the calculator include ceilings?
Yes, when you add a separate ceiling surface. Room mode includes only the four walls, so ceilings are never silently added or counted twice.
Should I subtract every opening?
Enter the combined opening area you want to exclude. Leaving small openings included provides extra material, but do not deduct an opening twice. Check your allowance against the actual layout.
Can area determine tape and screw quantities?
Not precisely. Seams, board layout, framing, installation requirements, and finishing details affect these supplies. Enter manual package quantities, or use a product's area-coverage guidance when appropriate.
Does this choose board thickness or optimize cuts?
No. Select suitable products for your installation and enter their dimensions and weights. This is an area-based purchasing estimate, not a cut layout, fastening schedule, structural assessment, or fire-rating specification.
What does the weight include?
It includes purchased board sheets only, using your entered per-sheet weights. Packaging, supplies, moisture differences, labor, delivery, and disposal are excluded from the relevant estimates.
