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Drywall calculator: sheets, mud, tape and screws

Work out how much drywall a room or a whole job needs. Enter the wall length, height, ceiling area and openings, choose the sheet size you hang, and get the sheets to order with waste — plus the joint compound, tape and screws that go with them.

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Tool 11

Drywall: sheets, mud, tape & screws

Enter the room or the total wall length, the height and the openings, and get the board area, the number of sheets in the size you hang, and the finishing materials to order with it.

The room

Result

Board area = wall length × height + ceiling − 21 sq ft per door − 15 sq ft per window. Sheets = board area × (1 + waste %) ÷ sheet area, rounded up. Finishing materials use common planning rates per 1,000 sq ft of board: about 370 ft of paper tape, 140 lb (≈ 2.3 boxes) of ready-mixed all-purpose compound for a level 4 finish, and about 1,000 screws. Your finisher’s own rates are better.

How to use it

  1. Enter the total wall length (the room’s perimeter) and the wall height.
  2. Enter the ceiling area, or 0 to leave the ceiling out.
  3. Enter the number of doors and windows to deduct.
  4. Choose the sheet size and waste allowance, and read the sheets and finishing materials.

A worked example

A 14 × 12 ft room with 8 ft walls has 416 sq ft of wall and 168 sq ft of ceiling. Less one door and two windows (51 sq ft) that is 533 sq ft of board. With 12% waste it takes 19 sheets of 4 × 8 — or 13 sheets of 4 × 12 with fewer joints to finish — about 2 boxes of ready-mixed compound, one 250 ft roll of tape for the 197 ft needed, and 533 screws.
Quantities are half the job. The trade guide covers what to track once the material is ordered — unit costs, waste against the estimate, and the software that shows them.
Read: Software for drywall contractors →

Questions

How do you calculate how many sheets of drywall you need?

Add the wall area (perimeter × height) and the ceiling area, subtract doors and windows, add 10–15% for waste, and divide by the sheet area: 32 sq ft for 4 × 8, 48 sq ft for 4 × 12.

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

With 8 ft walls, the walls are 384 sq ft and the ceiling 144 sq ft — 528 sq ft before openings. That is about 19 sheets of 4 × 8 with 12% waste, before deducting doors and windows.

How much joint compound do I need?

A common planning figure is about 140 lb of ready-mixed all-purpose compound per 1,000 sq ft of board for a level 4 finish — a little over two 4.5-gallon boxes. Higher finish levels use more.

Should I use 4 × 8 or 4 × 12 drywall?

Longer sheets mean fewer butt joints, and butt joints take the most finishing time. Crews hanging 8 ft walls horizontally often prefer 12 ft sheets when they can get them into the room.

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Want this on your live data, every morning?

These tools are manual. The dashboard does the same arithmetic across every job, every company and every week — plus the money-at-risk view, the audit findings and the overrun radar. Join the private beta and we will connect it to the systems you already run.