What size drywall sheets should I buy?

4x8 sheets are easiest to move through doorways and stairs. 4x12 sheets cover more area with fewer seams but are heavy — this calculator shows both.

Drywall Calculator — Sheets Needed for a Room

Drywall Calculator

Estimate the square footage of drywall needed for walls and ceilings — and how many 4x8 or 4x12 sheets to buy.

Room length (feet)

Room width (feet)

Wall height (feet)

Include ceiling?

Doors + windows (total sq ft)

Waste allowance (%)

4x8 sheets (32 sq ft each)

4x12 sheets (48 sq ft each)

Estimates only. Add extra for closets, odd angles and future repairs.

How this drywall calculator works

Wall area is the room perimeter (2 × length + 2 × width) times the wall height. If you are also covering the ceiling, add the floor area. Subtract doors and windows, then apply a waste allowance — 10% is a good default for rooms with corners and doorways.

Drywall is sold in 4x8 (32 sq ft) and 4x12 (48 sq ft) sheets. Bigger sheets mean fewer seams, but they are heavy and hard to get through small openings — for a typical room, 4x8 is the practical choice, and this calculator shows both counts.

Drywall tips

Never cut sheets narrower than about 2 feet — a thin strip is hard to mud cleanly.
Order 10-15% extra: broken corners and angled cuts eat sheets.
Use 1/2 inch thickness for walls, 5/8 inch for ceilings and fire-rated areas.

Frequently asked questions

How many drywall sheets do I need for a room?

A 12 × 10 ft room with 8 ft walls has about 352 sq ft of wall area — 11 sheets of 4x8, or 13 with a 10% waste allowance.

Should I include the ceiling?

Only if you are covering it too. There is a dropdown for that in the calculator.

Should I buy 4x8 or 4x12 sheets?

4x8 for rooms and stairs; 4x12 for large open walls where fewer seams matter more than weight.

Drywall Calculator

How this drywall calculator works

Drywall tips

Frequently asked questions

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