Drywall Calculator - Calculate Sheets, Mud, Tape, and Screws
Free drywall calculator. Calculate exact sheets, joint compound, tape, and screws needed for any room. Supports 4x8, 4x10, and 4x12 sheet sizes.
Room Dimensions
Corner Bead
Standard rectangular room has 4 outside corners
Enter room dimensions to see results.
About This Calculator
How to Calculate Drywall Needed
Measuring Tips
- Measure length and height of each wall in feet
- For ceilings, measure length and width
- Subtract door and window openings (typically 21 sq ft for doors, 15 sq ft for windows)
- Calculate each surface separately for accuracy
- Add 10% for waste, cuts, and mistakes
Drywall Size Guide
| Sheet Size | Sq Ft | Best For |
|---|---|---|
| 4×8 | 32 | Standard walls, easy handling |
| 4×10 | 40 | 10-foot ceilings, fewer seams |
| 4×12 | 48 | Large rooms, commercial work |
Tips for Best Results
- Hang drywall horizontally to reduce seams
- Stagger joints between rows for strength
- Use 5/8-inch drywall for ceilings to prevent sagging
- Apply three thin coats of mud rather than one thick coat
- Sand between coats for a smooth finish
Frequently Asked Questions
How do I calculate how many drywall sheets I need?
Measure the total square footage of all walls and ceilings. Divide by the square footage of one sheet (4×8 = 32 sq ft, 4×10 = 40 sq ft, 4×12 = 48 sq ft). Add 10% for waste and cuts. For example, a 12×12 room with 8ft ceilings: (4 walls × 12ft × 8ft) = 384 sq ft ÷ 32 = 12 sheets + 10% = 13-14 sheets.
How much joint compound do I need per sheet of drywall?
Plan for approximately 0.5-1 gallon of joint compound per sheet of drywall for three coats. This includes taping, first coat, and finish coat. A 5-gallon bucket covers approximately 25-35 sheets depending on application technique.
How many screws do I need per sheet of drywall?
Use 28-32 screws per 4×8 sheet for walls (screws every 12 inches on edges, 16 inches in field). For ceilings, use 36-40 screws per sheet (every 8 inches on edges, 12 inches in field). Use coarse-thread screws for wood studs, fine-thread for metal.
Should I hang drywall vertically or horizontally?
Hang drywall horizontally on walls to reduce the number of seams and make taping easier. Horizontal installation also helps with structural bracing. For 8-foot ceilings, use 4×12 sheets horizontally. Vertical installation may be better for short walls or when working alone.
What size drywall sheets should I use?
4×8 sheets are standard and easiest to handle. 4×10 sheets reduce seams on 10-foot walls. 4×12 sheets are best for large open areas with 12-foot ceilings. Thicker 5/8-inch drywall is required for ceilings and fire-rated walls, while 1/2-inch works for standard walls.