Drywall Calculator
Calculate drywall sheets and screws needed by wall and ceiling area. Includes waste factor and supports both 4×8 and 4×1
Project Information
Room Area
Wall + ceiling area
Openings
Electrical panels, etc.
Drywall Requirements
Total Project Cost
$3.69 per sq ft
Sheets Needed
4x8 sheets
Net Area
After openings
Cost Breakdown
Supply List
Project Timeline
🔨 Installation Tips
- • Measure twice, cut once - minimize waste
- • Use proper screws: 1¼" for ½" drywall
- • Apply thin, even coats of mud
- • Sand between coats for smooth finish
- • Use mesh tape for repairs, paper for new work
How it works
A drywall calculator finds how many sheets a room needs by dividing the total wall and ceiling area by the area of one sheet. A standard 4×8 sheet covers 32 square feet; a 4×12 covers 48.
Drywall sheets
Sheets = total area (ft²) ÷ sheet area (ft²)
- total area
- walls + ceiling to be covered
- sheet area
- 32 ft² (4×8) or 48 ft² (4×12)
Worked example
- Total area = 640 sq ft
- Using 4×8 sheets (32 ft² each)
- Sheets = 640 ÷ 32
20 sheets — add ~10% for cuts and waste, so order ~22.
Good to know
- Larger sheets mean fewer seams to tape, but they're heavier and harder to handle solo.
- Add 10–15% for waste, especially in rooms with many doors, windows, or corners.
- Don't forget joint compound, tape, and screws — roughly one screw per square foot of framing.
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Frequently Asked Questions
How many drywall sheets do I need?
Total the wall and ceiling areas, subtract large openings like doors and windows, divide by the sheet area (32 sq ft for 4×8, 48 sq ft for 4×12), and add about 10–15% for waste. A 12 × 12 room with 8 ft ceilings needs roughly 13–14 4×8 sheets for walls and ceiling.
Should I use 4×8 or 4×12 sheets?
4×12 sheets cover more area with fewer seams to tape and finish, which saves significant labor on long walls and big ceilings. 4×8 sheets are lighter and far easier to haul and maneuver in small rooms, stairways, and DIY jobs.
What thickness of drywall should I use?
1/2-inch is the standard for walls; 5/8-inch is used on ceilings (to prevent sag) and wherever a fire-rated assembly is required, such as attached garages. 1/4-inch panels are for curved surfaces and overlaying existing walls.
How many screws do I need per sheet?
Roughly 32 screws for a 4×8 sheet on walls — screws every 16 inches in the field and every 8–12 inches along edges, per typical spacing requirements. Ceilings use tighter spacing, so plan on more; a pound of 1-1/4" coarse screws covers about 5–6 sheets.
What else do I need besides the boards?
Joint tape and compound for every seam, corner bead for outside corners, and screws or adhesive. As a rule of thumb, figure about one 4.5-gallon bucket of joint compound and 500 ft of tape per 1,000 sq ft of drywall.