Drywall Calculator
Enter room dimensions or pick a preset to calculate drywall sheets, joint compound, tape, and screws for your project. Adjust waste factor and sheet size for accurate estimates.
About Drywall Materials
Drywall Sheet Sizes
Standard drywall comes in three common sizes:
- 4' x 8' (32 sq ft) -- Most common, easier to handle, good for standard walls
- 4' x 10' (40 sq ft) -- Good middle ground for 9-foot ceilings, fewer seams than 4x8
- 4' x 12' (48 sq ft) -- Covers more area, reduces seams, better for ceilings and tall walls
Material Estimations
- Joint Compound -- Approximately 1 gallon per 100 sq ft for full taping and finishing (three coats)
- Drywall Tape -- Roughly 1 linear foot of tape per 1 sq ft of drywall (accounts for all seams)
- Screws -- Approximately 32 screws per 4x8 sheet, spaced 12-16 inches on studs
Waste Factor
Always add extra material for cuts, mistakes, and irregular spaces:
- 5-7% -- Simple rectangular rooms with very few cuts
- 8-10% -- Standard rooms with typical doors and windows
- 11-15% -- Complex layouts, angled walls, or many cutouts
Installation Tips
- Always install drywall perpendicular to studs or joists
- Stagger seams between rows to avoid long continuous joints
- Use moisture-resistant "green board" or cement board in bathrooms and kitchens
- For ceilings, use 5/8" thickness to prevent sagging; 1/2" is standard for walls
- Standard opening assumption: 20 sq ft per door/window (adjust for large windows or patio doors)
Frequently Asked Questions
How many sheets of drywall do I need?
What size drywall should I use?
How much joint compound do I need?
Should I use paper or mesh tape?
How many screws per sheet of drywall?
What is the standard opening size for doors and windows?
Should I include the ceiling?
Privacy & Limitations
- All calculations run entirely in your browser -- nothing is sent to any server.
- Results are estimates and may vary based on actual conditions.
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Drywall Calculator FAQ
How many sheets of drywall do I need?
Measure the wall area (length x height for each wall), add ceiling area if needed, subtract openings, then divide by sheet size (32 sq ft for 4x8 or 48 sq ft for 4x12). Add 10-20% waste factor and round up to the nearest whole sheet.
What size drywall should I use?
For walls with 8-foot ceilings, use 4x8 sheets. For taller walls or ceilings, use 4x12 sheets to reduce seams. 1/2 inch thick is standard for walls; 5/8 inch is recommended for ceilings to prevent sagging.
How much joint compound do I need?
Plan for 1 gallon of joint compound per 100 sq ft of drywall. This covers three coats: taping, second coat, and final finishing. For texture application, you may need 50% more.
Should I use paper or mesh tape?
Paper tape is stronger and preferred for flat seams. Mesh tape is self-adhesive and easier for beginners but requires more compound. This calculator assumes standard paper tape.
How many screws per sheet of drywall?
Approximately 32 screws per 4x8 sheet when placed 12-16 inches apart on studs 16 inches on center. Use 1.25 inch screws for 1/2 inch drywall and 1.625 inch screws for 5/8 inch drywall.
What is the standard opening size for doors and windows?
This calculator assumes 20 sq ft per opening (a standard 3 by 7 foot door is 21 sq ft). For large windows or patio doors, count them as 2 openings. For small windows, you may round down.
Should I include the ceiling?
Only include the ceiling if you are installing new drywall on it. Many renovation projects only replace wall drywall. Ceiling work is more difficult and often requires longer sheets (4x12) to minimize seams.