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Drywall calculator: sheets, joint compound, tape and screws

Enter the room’s length, width and wall height. You get the number of 4 × 8 or 4 × 12 sheets, with extra for cuts, and the joint compound, tape and screws to finish them.

By Martin Lashgari, Ph.D., P.E., PMP · Published 2026-10-18

Price this job with the drywall cost calculator →

The drywall cost calculator prices the same room hung and finished, to a level 4 or level 5 finish, or the materials alone. Quantities here and there come from the same factors, so the two always agree.

Drywall for common rooms

Walls 8 ft high plus the ceiling, with 10% extra for cuts.

Room4 × 8 sheets4 × 12 sheetsMud bucketsTape rolls
10 × 10 ft151021
12 × 12 ft191321
12 × 14 ft211421
14 × 16 ft251731
16 × 20 ft312131

How this calculator works

Wall area is the room’s perimeter × wall height, plus length × width for the ceiling. Sheets are that area with 10% extra for cuts, divided by 32 sq ft for a 4 × 8 sheet or 48 for a 4 × 12, rounded up.

Finishing supplies scale with area: one 5-gallon bucket of joint compound per 300 sq ft, one 500 ft roll of paper tape per 1,500 sq ft, and one 5-lb box of screws per 400 sq ft.

Doors and windows are not subtracted; their cut-outs cover breakage and offcuts you cannot reuse. These are the drywall cost calculator’s own factors.

Sources:

Quantities are for planning and ordering. Check the plan, the supplier’s product data and local code before you buy; for structural concrete, follow the drawings.

Frequently asked questions

How many sheets of drywall do I need for a 12x12 room?

A 12 × 12 ft room with 8 ft walls and a ceiling is 528 sq ft of drywall. With 10% extra for cuts that is 19 sheets of 4 × 8, or 13 sheets of 4 × 12.

Should I use 4x8 or 4x12 drywall sheets?

Longer 4 × 12 sheets mean fewer joints to tape, which saves finishing time on walls longer than 8 ft and on ceilings. They weigh about half again as much as a 4 × 8 and need two people, and they may not fit up a narrow stair.

How much joint compound and tape do I need?

Plan on one 5-gallon bucket of joint compound per 300 square feet of drywall and one 500 ft roll of tape per 1,500. A 12 × 12 room takes 2 buckets and 1 roll.

Should I subtract doors and windows from the drywall count?

Not for an estimate. Sheets are cut around openings, and those offcuts rarely fit anywhere else, so the full wall area is the better guide to how many sheets you will use.