Drywall Calculator
Estimate drywall sheets, area, joint compound, tape and screws in Imperial or Metric units.
Estimate drywall sheets, area, joint compound, drywall tape and screws for walls and ceilings using Imperial or Metric room dimensions, regional sheet sizes, opening deductions and a waste allowance.
Your Estimate
Gross Wall Area
512.0 sq ft
Ceiling Area
240.0 sq ft
Opening Deductions
51.0 sq ft
Net Drywall Area
701.0 sq ft
Area Including Waste
771.1 sq ft
Drywall Sheets
25 sheets
Estimated Joint Compound
1.54 gal
Estimated Drywall Tape
771.1 linear ft
Estimated Drywall Screws
800 screws
Rough planning estimates use 21 sq ft per door, 15 sq ft per window, one gallon of compound per 500 sq ft and one linear foot of tape per sq ft. Assumes 32 screws per sheet.
Results Actions
Opening deductions and sheet sizes are regional planning defaults. Measure oversized openings and confirm locally available sheet dimensions, compound packaging, tape rolls and fastening requirements before purchasing.
Drywall Estimating Reference
These are rough planning assumptions. Sheet dimensions and product packaging vary by region, and the listed metric sheet sizes are common examples rather than universal standards.
How to Use the Drywall Calculator
- 1Choose Imperial or Metric units, then enter room length, width and wall height in feet or meters.
- 2Choose whether to include the ceiling area.
- 3Enter the number of standard doors and windows to deduct from the drywall area.
- 4Select an Imperial sheet size or a native Metric sheet size available for that mode.
- 5Choose a 5%, 10% or 15% waste allowance.
- 6Review gross wall area, ceiling area, deductions, net area, sheets, joint compound, tape and screws.
Example Calculation
Imperial example: a 20 ft × 12 ft room with 8 ft walls, one door, two windows and a ceiling has 701 sq ft net area and 771.1 sq ft with 10% waste. Using 4 × 8 sheets requires 25 sheets, about 1.54 gal of compound, 771.1 linear ft of tape and 800 screws. Metric example: a 6 m × 3.6 m room with 2.4 m walls and the same openings has 62.95 m² net area and 69.25 m² with waste. Using 1200 × 2400 mm sheets requires 25 sheets, about 5.64 L of compound, 227.2 linear m of tape and 800 screws.
Accuracy & Assumptions
- Results are estimates only.
- Imperial openings are deducted at 21 sq ft per door and 15 sq ft per window; Metric openings use approximately 1.95 m² and 1.39 m².
- Metric sheet sizes are native regional examples and are not universal worldwide product dimensions.
- Sheet coverage, joint compound use, tape length and screw counts vary by layout, seam count and manufacturer.
- The calculator assumes about 32 screws per sheet for planning purposes.
- Joint compound assumes 1 gal per 500 sq ft, converted to 3.785 L per 46.45 m² in Metric mode.
- Tape assumes 1 linear ft per sq ft of waste-adjusted drywall area and converts that length to meters in Metric mode.
- Verify room measurements and opening sizes before purchasing materials.
- Check local building codes and manufacturer guidance for fire-rated or moisture-resistant board requirements.
Frequently Asked Questions
How do I calculate how many drywall sheets I need?
Calculate gross wall area from room perimeter times wall height, add ceiling area if needed, subtract standard door and window openings, add waste, then divide by the square footage of one drywall sheet. The calculator rounds up to whole sheets.
What drywall sheet size should I choose?
Imperial mode offers 4 × 8, 4 × 10 and 4 × 12 ft sheets. Metric mode offers 1200 × 2400, 1200 × 3000 and 1200 × 3600 mm examples. Available dimensions vary by country and supplier.
How much waste should I add for drywall?
Use 10% waste for most straightforward rooms. Increase to 15% or more for rooms with many closets, soffits, windows, doors, angled cuts, or ceiling work.
Does this calculator include ceilings?
Yes, if you choose "Yes" for Include ceiling. The calculator adds room length times room width as ceiling area. Choose "No" if you are only hanging drywall on the walls.
How are doors and windows deducted?
Imperial mode subtracts 21 sq ft per door and 15 sq ft per window. Metric mode uses approximately 1.95 m² and 1.39 m². Oversized or unusual openings need a manual adjustment.
How many screws do I need per drywall sheet?
This calculator uses about 32 screws per sheet as a planning estimate. Actual screw count varies with stud spacing, ceiling installation, panel thickness, and local fastening requirements.
Does this estimate joint compound and tape?
Yes. It estimates compound in gallons or liters and tape in linear feet or meters. Finishing style, seam count, corner bead, texture, product coverage and coat count can change real usage.
This calculator provides a planning estimate only. Sheet dimensions, product packaging and construction practices vary by region, and the included metric sheet sizes are not universal. Screw spacing, finish level, compound use, tape length and moisture-resistant or fire-rated board requirements vary by project — confirm final quantities and product requirements with your supplier, contractor, manufacturer or local authority before purchasing.