Drywall Calculator
Enter your wall and ceiling area to estimate the number of 4×8 or 4×12 drywall sheets needed, with a waste factor.
Results
- Drywall sheets
- 28
- Surface area
- 800 sq ft
Estimates only. Round up and buy a little extra to account for waste, spills, and breakage.
Enter your wall and ceiling area to estimate the number of 4×8 or 4×12 drywall sheets needed, with a waste factor.
Also used as a sheetrock calculator and drywall sheet estimator.
How to use the drywall calculator
- Enter the total surface area in sq ft.
- Enter the sheet size.
- Enter the waste factor in %.
- Optionally add a price to estimate the total project cost.
- Read your quantities instantly — no sign-up, and you can print the estimate to take to the supplier.
Worked example
Inputs
- Total surface area
- 800 sq ft
- Sheet size
- 4 × 8 ft (32 sq ft)
- Waste factor
- 10 %
Results
- Drywall sheets
- 28
- Surface area
- 800 sq ft
Using the example values above, the drywall calculator returns 28 (drywall sheets). Change any field to match your own project and the numbers update instantly.
How much extra should I order?
Always order a little extra. A 5% waste factor suits simple, square projects; 10% is right for most jobs; bump it to 15–20% for irregular shapes, diagonal patterns, or uneven ground. Running short almost always costs more than the leftover material.
Cubic yard coverage by depth
| Depth | Coverage per cu yd |
|---|---|
| 1 in | 324 sq ft |
| 2 in | 162 sq ft |
| 3 in | 108 sq ft |
| 4 in | 81 sq ft |
| 6 in | 54 sq ft |
Formula
Sheets = total area ÷ sheet area, × (1 + waste%). 4×8 = 32 sq ft, 4×12 = 48 sq ft.
Frequently asked questions
- What size drywall should I buy?
- 4×12 sheets reduce seams on long walls; 4×8 sheets are easier to handle solo.
- How much drywall waste should I plan?
- Add 10–15% for cutouts around windows, doors, and outlets.
- How many sheets of drywall do I need?
- Add up all wall and ceiling area, then divide by 32 sq ft for 4×8 sheets or 48 sq ft for 4×12 sheets, plus 10–15% for cutouts.
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How Much Drywall Do I Need?
Estimate drywall sheets for walls and ceilings, with 4×8 and 4×12 sheet coverage.