🏗️ Drywall Calculator
Calculate drywall sheets needed
How to Use This Calculator
Enter Room Dimensions
Input the length and width of your room in feet. Measure the room from wall to wall for accurate calculations. For irregular shapes, break into rectangles.
Specify Wall Height
Select the wall height in feet. Standard heights are 8 feet (common), 9 feet (tall), 10 feet (very tall), or 12 feet (commercial). Use 4×12 sheets for walls taller than 8 feet.
Calculate Drywall Needs
Click "Calculate Drywall" to see wall area and number of sheets needed. The calculator shows both 4×8 sheets (32 sq ft) and 4×12 sheets (48 sq ft).
Order Materials
Add 10-15% extra for waste, cuts, mistakes, and doors/windows. Order additional sheets for ceilings if needed. Use 4×12 sheets for 9+ foot walls to minimize seams.
Formula
Wall Area = 2 × (Length + Width) × Height
4×8 Sheets Needed = Wall Area ÷ 32
4×12 Sheets Needed = Wall Area ÷ 48
Example 1: Standard Room (20 ft × 15 ft × 8 ft)
Step 1: Calculate wall area: 2 × (20 + 15) × 8 = 2 × 35 × 8 = 560 sq ft
Step 2: Calculate 4×8 sheets: 560 ÷ 32 = 17.5 → 18 sheets
Step 3: Calculate 4×12 sheets: 560 ÷ 48 = 11.7 → 12 sheets
Step 4: Add waste: 18 × 1.15 = 21 sheets (with 15% waste)
Example 2: Tall Room (18 ft × 12 ft × 10 ft)
Step 1: Calculate wall area: 2 × (18 + 12) × 10 = 2 × 30 × 10 = 600 sq ft
Step 2: Calculate 4×8 sheets: 600 ÷ 32 = 18.75 → 19 sheets
Step 3: Calculate 4×12 sheets: 600 ÷ 48 = 12.5 → 13 sheets (recommended for 10 ft walls)
Step 4: Add waste: 13 × 1.15 = 15 sheets (with 15% waste)
About Drywall Calculator
The Drywall Calculator is an essential tool for contractors, builders, drywallers, and DIY enthusiasts who need to accurately determine how many drywall sheets are required for their projects. This calculator eliminates guesswork by providing precise sheet counts for both standard 4×8 sheets and larger 4×12 sheets, helping you order the right amount of materials without waste or shortages.
When to Use This Calculator
- New Construction: Calculate drywall needed for new room construction and additions
- Room Renovations: Determine drywall quantities for remodeling and renovation projects
- Drywall Replacement: Estimate materials for replacing damaged or old drywall
- Contractor Estimates: Quick reference for contractors bidding drywall projects
- Budget Planning: Calculate material costs by determining exact sheet quantities needed
Why Use Our Calculator?
- ✅ Accurate Measurements: Precise wall area calculations prevent over-ordering or running short
- ✅ Multiple Sheet Sizes: Shows both 4×8 sheets (32 sq ft) and 4×12 sheets (48 sq ft) for different wall heights
- ✅ Waste Allowance: Automatically accounts for doors and windows; add 10-15% extra for waste
- ✅ Cost Planning: Helps budget accurately by determining exact material needs
- ✅ Time Savings: Instant calculations eliminate manual math and measurements
- ✅ Professional Results: Industry-standard formulas ensure contractor-quality estimates
Common Applications
Residential Construction: Homeowners and contractors planning new rooms or additions use this calculator to order the correct quantity of drywall sheets. Standard rooms use 4×8 sheets, while tall rooms (9+ feet) benefit from 4×12 sheets to minimize seams.
Commercial Projects: Contractors working on commercial buildings use this tool to estimate drywall quantities for offices, retail spaces, and commercial spaces, ensuring sufficient materials are on-site before starting work.
Room Renovations: DIY enthusiasts and contractors planning room renovations use this calculator to determine drywall quantities needed for remodeling projects, avoiding costly mistakes from ordering too little or too much.
Tips for Best Results
- Sheet Sizes: Use 4×8 sheets for walls up to 8 feet; use 4×12 sheets for 9+ foot walls to minimize seams
- Thickness: Use 1/2 inch for walls, 5/8 inch for ceilings; fire-rated drywall for garages
- Add Waste: Always add 10-15% extra for waste, cuts around doors/windows, and mistakes
- Account for Ceilings: Add ceiling area separately if calculating both walls and ceilings
- Order Together: Order all drywall from the same batch for consistency in texture and color
Frequently Asked Questions
How many drywall sheets do I need for a 20×15 foot room with 8-foot walls?
For a 20×15 foot room with 8-foot walls (560 sq ft wall area), you'll need approximately 18 sheets of 4×8 drywall, or 12 sheets of 4×12 drywall. Add 10-15% extra (2-3 sheets) for waste and cuts around doors/windows.
Should I use 4×8 or 4×12 sheets?
Use 4×8 sheets for walls up to 8 feet tall (standard). Use 4×12 sheets for walls 9-12 feet tall to minimize seams and horizontal joints. Fewer seams mean less taping and a smoother finish.
How do I calculate drywall for doors and windows?
The calculator doesn't subtract doors/windows automatically. For accuracy, calculate each wall separately or subtract door/window areas manually. Most standard doors are 20-30 sq ft, windows are 15-25 sq ft each.
Do I need to add extra drywall for waste?
Yes! Always add 10-15% extra for waste, cuts around doors/windows, electrical boxes, and mistakes. For complex rooms with many angles, add 15-20% extra. It's better to have a little extra than to run short.
What thickness drywall should I use?
Standard thickness: 1/2 inch for walls (most common), 5/8 inch for ceilings (less sag). Use 5/8 inch or fire-rated drywall for garages and attached spaces. Thicker drywall is stronger but heavier and more expensive.
How do I calculate drywall for ceilings?
Calculate ceiling separately: Ceiling Area = Length × Width. Then divide by 32 (for 4×8 sheets) or 48 (for 4×12 sheets). Add 10-15% waste. Use 5/8 inch thickness for ceilings to prevent sagging.