Drywall Calculator
Calculate how many drywall sheets, tape, joint compound, and screws you need for walls and ceilings.
How It Works
This calculator estimates drywall sheets for both walls and ceiling, plus the joint tape, mud, and screws needed to finish the job.
Wall area: Perimeter × Ceiling Height − door openings (21 sq ft each) − window openings (12 sq ft each).
Ceiling area: Room Length × Room Width.
Sheet counts include 10% waste for cuts and fitting. Joint tape is estimated at half the perimeter of each sheet (seams along length and width). Joint compound is roughly 1 gallon per 100 sq ft. Screw count uses 1.2 screws per sq ft.
Frequently Asked Questions
How many sheets of drywall do I need?
Measure the total wall area (perimeter times ceiling height) and ceiling area (length times width). Subtract openings like doors (~21 sq ft each) and windows (~12 sq ft each). Divide total square footage by the sheet size (32 sq ft for 4x8 or 48 sq ft for 4x12) and add 10% for waste.
Should I use 4x8 or 4x12 drywall sheets?
Use 4x12 sheets for rooms with 9-foot or higher ceilings to reduce horizontal seams. For standard 8-foot ceilings, 4x8 sheets are the most common choice. Longer sheets mean fewer joints to tape but are heavier and harder to handle.
How much joint compound do I need?
Plan for approximately 1 gallon of joint compound (mud) per 100 square feet of drywall. A standard 4.5-gallon bucket covers about 450 square feet. You will need three coats: taping, second coat, and finish coat.
How many drywall screws per sheet?
Use about 28-32 screws per 4x8 sheet, or roughly 1.2 screws per square foot. Screws should be spaced 12 inches apart on ceilings and 16 inches apart on walls, placed at every framing member (stud or joist).
Do I need to drywall the ceiling too?
Yes, in most finished rooms the ceiling gets drywall. This calculator includes both wall and ceiling sheets in the total. For garages or utility rooms, you may skip ceiling drywall unless fire code requires it.