Drywall Calculator

Enter your room size to see how many sheets of drywall and screws to buy.

How the calculation works

area = 2 × (length + width) × height − 21 sq ft per door − 15 sq ft per window (+ ceiling)

Add 10% for cuts and waste, then divide by the sheet size and round up. For screws, the estimate uses about 1 screw per square foot of board. That's typical for 16" stud spacing, with screws every 12" on walls and a little closer on ceilings.

Worked example

A 14 × 12 room with 8 foot walls, one door and two windows has 365 sq ft of wall. With the 168 sq ft ceiling, the total is 533 sq ft, or 586 with 10% waste. That's 19 sheets of 4 × 8 or 13 sheets of 4 × 12, plus about 590 screws.

Tips

• Use the longest sheets you can carry in. Fewer seams means less taping and a smoother finish.
• Hang the ceiling first, then the walls, so the wall sheets support the ceiling edges.
• Use 1/2" board on walls. On ceilings with 24" framing, use 5/8" or sag-resistant 1/2".

Frequently asked questions

How many sheets of drywall for a 12 × 12 room?

With 8 foot walls, about 384 sq ft of wall before openings. That's 12 to 14 sheets of 4 × 8 for the walls, and 5 more for the ceiling, including waste.

Should I subtract doors and windows?

Yes for the estimate, but most of the cut-outs become waste anyway. That's why the 10% allowance matters.