🧱 Drywall Calculator

Enter the area you're covering to find out how many sheets of drywall you need — plus screws, joint compound, and tape, with a waste factor and total cost.

Area to cover
sq ft Add up all wall and ceiling surfaces you're drywalling.
Sheet size
Waste & price
%
$
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How to calculate how much drywall you need

Drywall is sold in sheets, so the job is to work out your total surface area and divide by the area of one sheet. The method is: add up every wall and ceiling, add a waste allowance, then divide by the sheet size and round up. This calculator also estimates the screws, joint compound, and tape so you can buy everything in one trip.

The formula, step by step

1. Total area = all wall surfaces + ceiling (if drywalling it).
2. With waste = total area × (1 + waste % ÷ 100).
3. Sheets = area with waste ÷ sheet area (32 sq ft for 4×8, 48 for 4×12).
4. Screws / mud / tape scale with the drywall area.

Standard drywall sheet sizes

Sheet size Area Notes
4 × 8 ft32 sq ftEasiest to handle
4 × 9 ft36 sq ft9 ft walls
4 × 12 ft48 sq ftFewer seams, heavy

Don't forget mud, tape, and screws

For a typical job, plan on about 0.05 lb of joint compound and 0.4 linear feet of tape per square foot of drywall, plus roughly one screw per square foot. Bigger sheets mean fewer seams, which means less taping and mudding — one reason pros often choose 4×12 sheets despite the extra weight.

A note on openings

This calculator uses your gross wall area without subtracting doors and windows. For most rooms that's a feature, not a bug — the offcuts around openings are rarely reusable, so counting the full wall acts as built-in waste. For a room with very large openings, you can subtract those areas manually in "Total area" mode.