Drywall Calculator

Estimate sheets of drywall, joint compound, tape, and screws for walls and ceilings. Subtract openings for doors and windows automatically.

Drywall estimating means counting sheets, then calculating the consumables — joint compound, paper tape, and screws — needed to finish those sheets. This calculator subtracts standard door and window openings from total wall area, applies a waste factor, and outputs all four quantities so you can place a single supplier order.

Frequently Asked Questions

Should I use 4×8 or 4×12 drywall sheets?

4×12 sheets reduce the number of joints on walls with 8-foot or taller ceilings. Fewer joints mean less taping and mudding. However, 4×12 sheets are heavier and harder to handle — many DIYers prefer 4×8.

How much joint compound do I need per sheet?

Approximately 0.25–0.35 gallons of premixed joint compound per 4×8 sheet (all three coats). A 5-gallon bucket covers roughly 15–20 sheets.

What thickness drywall should I use?

½" is standard for most residential walls and ceilings. ⅝" (Type X) is required for garage-to-house walls and ceilings below living spaces per IRC fire separation requirements.

Estimates are for planning purposes only. Verify quantities with your supplier and confirm code requirements with your local building department.