DRYWALL
DRYWALL SHEETS
sheets = area ÷ 32 × 1.10
ft
ft
ft
RESULT
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Based on 4×8 (32 ft²) sheets with 10% waste. For 4×12 sheets, divide result by 1.5.
About this calculator
Use this drywall calculator to estimate how many sheets of 4x8 drywall (sheetrock) you need to finish a room. Enter the room dimensions and ceiling height, choose whether you are covering the ceiling, and the calculator returns the exact sheet count rounded up with a 10% waste factor built in. Standard 4x8 sheets cover 32 square feet each. For 4x12 sheets divide the result by 1.5.
Common questions
How much does a sheet of drywall cost?
A standard 4×8 ft sheet of ½-inch drywall runs $13–18 at Home Depot or Lowe's as of 2026. Moisture-resistant (greenboard) and fire-rated (Type X) sheets run $18–28. 4×12 sheets cost roughly 1.5× the 4×8 price — slightly cheaper per square foot but harder to handle solo.
Should I buy 4×8 or 4×12 drywall sheets?
4×8 is easier for one person to handle and fits most rooms with less waste. 4×12 reduces seams (faster mudding, smoother finish) but requires two people and a truck. For ceilings or rooms over 12 ft on the long side, 4×12 saves time. Most DIYers stick with 4×8.
Do I need to subtract windows and doors?
For most jobs, no — leaving the openings in your calculation gives you natural waste tolerance for cuts. If your room has unusually large openings (sliding glass doors, picture windows totaling more than 50 ft²), subtract them to avoid over-buying.