How do you calculate drywall sheets?
Multiply wall perimeter by wall height, add ceiling area if needed, subtract openings, add waste, then divide by the square footage of one drywall sheet and round up.
Free renovation calculator
Free Drywall Calculator
A drywall calculator estimates how many drywall sheets and finishing supplies a room needs from its dimensions. Use this tool to plan wall and ceiling coverage, subtract common openings, add waste, and price materials before you buy.
Room and material inputs
Material shopping list
20 drywall sheets cover 608.3 sq ft after 10% waste.
Joint compound
2 buckets
Drywall tape
1 roll
Drywall screws
4 boxes
Wall area
448 sq ft
Gross drywall area
Walls plus ceiling before opening deductions
640 sq ft
Net coverage area
2 doors and 3 windows removed
553 sq ft
Waste allowance
10% extra for cuts, corners, and mistakes
55.3 sq ft
Sheet size
4 ft x 8 ft drywall sheets
32 sq ft
Planning notes
- Buy 20 drywall sheets for about $280 before tax or delivery.
- Plan on 2 buckets of joint compound, 1 tape roll, and 4 screw boxes.
- Estimated material cost is $359 with the prices entered here.
How to use the drywall calculator
- 1
Enter the room dimensions
Add the room length, width, wall height, and number of matching rooms.
- 2
Choose whether to include the ceiling
Include the ceiling when you are hanging drywall overhead as well as on walls.
- 3
Subtract common openings
Enter door and window counts so the calculator can remove typical opening areas.
- 4
Set sheet size, waste, and prices
Choose your drywall sheet size and local material prices for sheets, mud, tape, and screws.
- 5
Review the shopping estimate
Use the result as a material planning estimate before confirming exact quantities with your installer or supplier.
Drywall calculator FAQ
How much waste should I add for drywall?
Most small room estimates use 10% to 15% waste. Use more for closets, angled ceilings, many corners, or rooms with complicated cuts.
Does this drywall calculator include ceilings?
Yes. Turn on the ceiling option when you are hanging drywall on the ceiling as well as the walls.
How many screws are needed per drywall sheet?
This calculator budgets one 200-count screw box for every five sheets. Local fastening schedules and framing layout can change the exact screw count.
Should I subtract doors and windows from drywall area?
Yes for material estimates. This calculator subtracts 21 square feet per door and 15 square feet per window as practical planning defaults.
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