Step 1
Measure the surfaces
Enter the room dimensions or use a known net drywall area.
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Drywall material and cost planning
Drywall Calculator
Estimate drywall sheets for walls and ceilings, subtract doors and windows, add waste, and calculate screws, tape, joint compound, corner bead, coverage, and material cost.
Drywall area
Walls + ceiling
Sheet quantity
Coverage + waste
Materials
Fasteners + finish
What this calculator includes
Surface areawalls + ceilings
Openingsdoors + windows
Drywall ordersheets + waste
Accessoriesscrews + tape + compound
Project estimatematerials + cost
Inputs
Drywall project details
Calculate walls, ceilings, or both from room dimensions, or enter a known drywall area. Add openings, waste, panel size, product coverage, and supplier pricing.
Room dimensions
Door and window deductions
Panel size and waste
Drywall screws
Joint tape and compound
Corner bead
Supplier pricing
Verify the installation system
Drywall thickness, fire or moisture rating, framing spacing, orientation, fastening schedule, joint layout, finish level, compound type, and product coverage can change the final order.
Results
Drywall shopping list
Review calculated surface area, whole-sheet quantities, fasteners, finishing materials, and estimated cost.
Drywall sheets
17 sheets
Purchase drywall area
531.3 sq ft
Joint compound
2 containers
Estimated material total
$0.00
Joint tape
1 roll
Screw boxes
1 box
Surface-area calculation
Calculation modeRoom dimensions
Selected surfacesWalls and ceiling
Gross wall area384 sq ft
Gross ceiling area144 sq ft
Opening deduction45 sq ft
Net drywall area483 sq ft
Waste allowance10%
Waste area48.3 sq ft
Purchase drywall area531.3 sq ft
Drywall sheets
Selected sheet size4 ft × 8 ft
Coverage per sheet32 sq ft
Sheets to purchase17 sheets
Purchased sheet coverage544 sq ft
Whole-sheet overage12.7 sq ft
Fasteners and finishing materials
Estimated drywall screws544 screws
Screw boxes1 box
Estimated joint tape185.95 lin ft
Joint-tape rolls1 roll
Joint-compound containers2 containers
Corner-bead pieces4 pieces
Material cost
Drywall sheet cost$0.00
Drywall screw cost$0.00
Joint-tape cost$0.00
Joint-compound cost$0.00
Corner-bead cost$0.00
Material subtotal$0.00
Estimated tax (0%)$0.00
Delivery fee$0.00
Additional fees$0.00
Estimated material total$0.00
Material cost per net square foot$0.00
Planning notes
- • Enter current supplier pricing to calculate a complete drywall material estimate.
How to calculate drywall for a room
Start by calculating the wall and ceiling surfaces that will receive drywall. Subtract applicable door and window openings, add a waste allowance, and divide the purchase area by the coverage of the selected sheet size. Always round material packages up to whole purchasable quantities.
Step 2
Deduct openings
Enter doors and windows when you want their areas removed from the estimate.
Step 3
Add waste and materials
Select a sheet size, add waste, and enter product coverage and pricing.
Drywall calculation formulas
Wall area
2 × (room length + room width) × wall height
This calculates the gross area of four rectangular walls.
Ceiling area
room length × room width
Include this area when the ceiling will also receive drywall.
Net drywall area
gross selected area − door area − window area
Opening deductions cannot reduce the result below zero.
Purchase area
net area × (1 + waste percentage ÷ 100)
Waste helps account for cuts, breakage, defects, and layout changes.
Drywall sheets
purchase area ÷ sheet coverage, rounded up
Sheets are rounded up because partial sheets cannot normally be purchased.
Estimated material cost
component costs + tax + delivery + additional fees
Enter current supplier prices for a location-specific planning estimate.
Choosing drywall sheet size
Standard four-foot-wide sheets are commonly available in several lengths. Longer sheets can reduce seams and finishing work, but they require more room for delivery, handling, and installation.
Verify sheet thickness, edge type, fire rating, moisture resistance, mold resistance, and local code requirements before purchasing.
Improving estimate accuracy
Divide irregular rooms into measurable rectangular surfaces. Measure large openings individually when their sizes differ substantially from the averages entered in the calculator.
Use the coverage and package information printed on the exact screws, tape, compound, and corner-bead products being purchased.
Planning and installation notice
This calculator provides a planning estimate, not a structural, code, fire-rating, or installation specification. Drywall requirements vary by assembly, framing, occupancy, moisture exposure, manufacturer instructions, and local building code. Confirm material selection, fastening schedules, finishing requirements, and safe lifting practices with qualified professionals.
Frequently asked questions
How do I calculate how many drywall sheets I need?
Calculate the net wall and ceiling area, add a waste allowance, divide by the coverage of one drywall sheet, and round the result up to a whole sheet.
Should doors and windows be deducted from drywall area?
Doors and windows can be deducted for a more precise material estimate. For small projects, some estimators leave minor openings included because the extra material can help cover cuts and damaged sheets.
How much waste should I add for drywall?
A waste allowance of about 10% is common for straightforward rooms. Complicated layouts, angled walls, numerous openings, short pieces, or inexperienced installation may require a higher allowance.
How many drywall screws and how much compound do I need?
Requirements vary with framing spacing, sheet orientation, fastening schedules, finish level, and product coverage. This calculator uses editable coverage inputs so you can match the products and installation requirements for your project.
What drywall sheet size should I use?
Four-foot-wide sheets are common, with lengths such as 8, 10, and 12 feet. Longer sheets can reduce seams but are heavier and more difficult to transport and install. Confirm the thickness, fire rating, moisture resistance, and sheet size required for the application.
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