Free tool

Drywall Calculator

Work out how many sheets of drywall you need for walls and ceilings, plus joint compound and tape. Then download or print a clean summary for your estimate.

4×8, 4×10, 4×12
Mud & tape
PDF summary

Your room

Size, openings and sheets

Enter one room. For several identical rooms, set "How many rooms".

Room length

Room width

Wall height

How many rooms?

Doors (21 sq ft each)

Windows (15 sq ft each)

Ceiling

Sheet size

Waste allowance

Price per sheet (optional)

Hanging and finishing labor usually costs more than the board. Price it with the employee cost calculator.

Your materials

Sheets, mud and tape

Updates as you type. Quantities are rounded up.

Drywall sheets

Compound

0 pails

Sheet cost

–

Wall area (after openings)0 sq ft

Ceiling area0 sq ft

Installed area0 sq ft

Waste0 sq ft

Area to order0 sq ft

Joint compound0.0 gal

Joint tape0 ft

Enter the room size to see how many sheets to buy.

Use this in my estimate

Pricing a drywall job?Build the full estimate in QuickEstimate: board, mud, tape, hanging and finishing labor, overhead and margin, sent as a proposal your client approves online.

Build a full estimate

How to Calculate How Much Drywall You Need

Drywall is sold by the sheet, so the job is to find the area you're covering and divide it by the area of one sheet. Measure the walls (and ceiling, if you're boarding it), subtract the big openings, add a waste allowance, and round up to whole sheets. Joint compound and tape are estimated from the installed area.

Drywall Formulas

Wall area

2 × (Length + Width) × Height − Openings

Sheets

(Wall area + Ceiling area) × (1 + Waste%) ÷ Sheet area

Compound and tape (rules of thumb)

≈ 10 gal compound and ≈ 370 ft tape per 1,000 sq ft

Drywall Sheet Sizes

Sheet	Area	Sheets per 1,000 sq ft	Best for
4 × 8 ft	32 sq ft	32	Easy handling, small rooms, solo work
4 × 10 ft	40 sq ft	25	9 ft walls hung horizontally
4 × 12 ft	48 sq ft	21	Fewer joints on long walls and ceilings

Worked Example: a 12 × 14 ft Room

A 12 × 14 ft room with 8 ft walls, one door and two windows, including the ceiling, with 10% waste:

12 × 14 ft room, 8 ft walls, walls + ceiling

Walls: 2 × (12 + 14) × 8 − 51365 sq ft

Ceiling: 12 × 14168 sq ft

Installed area533 sq ft

Add 10% waste586 sq ft

4 × 8 sheets: 586 ÷ 32, rounded up19 sheets

or 4 × 12 sheets: 586 ÷ 48, rounded up13 sheets

Compound: 533 × 10 ÷ 1,0005.3 gal (2 pails)

Tape: 533 × 370 ÷ 1,000197 ft (1 roll of 250 ft)

Tips for Accurate Drywall Estimates

Openings: many hangers board straight over small openings and cut them out, so they don't subtract them. Subtracting is fine for large doors and windows.
Ceilings often use 1/2 in sag-resistant or 5/8 in board. Price them separately if the board differs.
Moisture-resistant or fire-rated board for bathrooms and garages costs more. Split those rooms out.
Screws and corner bead are extra. Corner bead is measured by the linear foot of outside corners.
Finish level drives labor more than materials. A level 5 finish takes far more time and compound than level 3 or 4.

From Sheets to a Profitable Drywall Quote

Board is usually the smaller part of a drywall price. A quote that makes money also covers delivery, hanging, taping and finishing by finish level, sanding, cleanup, overhead and profit:

Price your crew at their true cost with the employee cost calculator
Set your price with the markup calculator or margin calculator
Send it as a professional quote with remodeling estimating software

Frequently Asked Questions

Find the wall area by multiplying the room's perimeter by the wall height, subtract doors and windows, and add the ceiling area if you're covering it. Add 10% for waste, then divide by the area of one sheet: 32 sq ft for 4 x 8, 40 sq ft for 4 x 10, or 48 sq ft for 4 x 12.

A 12 x 14 ft room with 8 ft walls, one door and two windows has about 365 sq ft of wall plus 168 sq ft of ceiling, 533 sq ft in total. With 10% waste that's about 586 sq ft, or 19 sheets of 4 x 8 drywall or 13 sheets of 4 x 12.

Larger sheets like 4 x 12 mean fewer joints to tape and finish, which saves labor. But they're heavy and awkward, especially on ceilings and in tight spaces, and usually need two people. 4 x 8 sheets are easier to handle and transport.

A common rule of thumb is about 10 gallons of ready-mixed joint compound per 1,000 sq ft of drywall for a standard finish. Higher finish levels and lots of corners use more.

Plan on roughly 370 feet of joint tape per 1,000 sq ft of drywall. Paper tape commonly comes in 250 ft and 500 ft rolls.

Yes. The drywall calculator is free, needs no signup, and runs entirely in your browser. Nothing you enter is sent to a server.