Drywall calculator: sheets, mud, tape and screws

Enter the room or the total area, pick a sheet size and a waste allowance. Get the sheets for the walls and the ceiling, the joint compound in gallons and pails, the paper tape in feet and rolls, and the screws, with every step shown.

9 galCompound per 1,000 sq ft

375 ftPaper tape per 1,000 sq ft

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Drywall sheets

17 sheets

4 × 8 ft (32 sq ft) for 492 sq ft, with 10% waste

1 × 4.5 galJoint compound

185 ftPaper tape

378Screws

Free. Your numbers become an estimate you can send from your phone.

How we got this

Wall area2 × (12 + 12) × 8 ft = 384 sq ft
Less openings1 door × 21 + 1 window × 15 = 36 sq ft, leaving 348 sq ft of wallMost hangers board right over small openings and cut them out after. Taking them off gives the true area to finish.
Ceiling12 × 12 ft = 144 sq ft
SheetsWalls 348 and ceiling 144 sq ft, each × 1.10 ÷ 32 sq ft a sheet, rounded up = 17 sheets (12 wall, 5 ceiling)Walls and ceiling are counted apart because a ceiling offcut rarely fits a wall. Ceilings often take 5/8 in board, so order them separately if the plans call for it.
Joint compound492 sq ft ÷ 1,000 × 9 gal = 4.4 gal (61 to 69 lb), 1 pail of 4.5 galNational Gypsum puts all-purpose ready-mix at 123 to 140 lb, or 9 gal, per 1,000 sq ft for tape, two finish coats and fasteners. USG says about two 4.5 gal pails per 1,000 sq ft.
Paper tape492 sq ft ÷ 1,000 × 375 ft = 185 ft, 1 roll of 250 ftNational Gypsum's figure for ProForm paper tape. Inside corners use the same tape, folded.
Screws492 sq ft ÷ 1,000 × 768 = 378 screwsFrom National Gypsum's estimating table. Ceilings and fire-rated walls can call for closer spacing; follow the plans.

Material	Quantity
Drywall sheets, 4 × 8 ft (32 sq ft)	17
All-purpose joint compound	4.4 gal (1 × 4.5 gal pails)
Paper joint tape	185 ft (1 × 250 ft rolls)
Drywall screws	378

Sources: National Gypsum, ProForm Construction Guide: Materials Estimating and Coverage table, compound and tape coverage; USG, What is the coverage rate for joint finishing? (two 4.5 gal pails per 1,000 sq ft). Checked 2026-10-08.

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Key takeaways

Sheets = area × (1 + waste) ÷ sheet area, rounded up. Count the walls and the ceiling apart, because ceiling offcuts rarely fit a wall.
National Gypsum puts ready-mix compound at 9 gal (123 to 140 lb) per 1,000 sq ft, paper tape at about 375 ft and screws at about 768. USG says about two 4.5 gal pails per 1,000 sq ft.
Longer sheets mean fewer joints to tape. A 4 × 12 sheet covers 50% more than a 4 × 8, if you can get it into the room.

How to calculate drywall for a room

Drywall is bought by the sheet and finished by the square foot. The math is the same whether you are hanging one bedroom or a whole basement:

Wall area. Add the room's length and width, double it to get the distance around the room, then multiply by the wall height. A 12 × 14 ft room with 8 ft walls is 2 × (12 + 14) × 8 = 416 sq ft.
Take off the openings. A standard 3 × 7 ft door is 21 sq ft, a 3 × 5 ft window 15 sq ft. One door and one window leave 416 − 36 = 380 sq ft.
Add the ceiling if you are hanging it: length × width, 12 × 14 = 168 sq ft.
Add waste for offcuts around openings, corners and the top course. Many hangers use about 10%. Your own jobs are the best guide.
Divide by the sheet area and round up: 32 sq ft for a 4 × 8, 40 for a 4 × 10, 48 for a 4 × 12.

The calculator counts the walls and the ceiling separately and rounds each up, because a ceiling sheet is usually cut to the room's width and its offcut is the wrong shape for a wall. That is closer to what you will really carry in than one combined number.

Board right over the openingsMost crews hang full sheets across small openings and cut them out with a router after. The openings still come off the finished area, which is what drives compound and tape, but on a room with many small windows you may use close to the gross wall area in sheets.

Drywall sheets by room size

These are worked with the calculator: 8 or 9 ft walls, one door, one window, the ceiling included and 10% waste. Walls and ceiling are rounded up separately.

Room	Walls	Area to finish	4 × 8 sheets	4 × 12 sheets
10 × 10 ft	8 ft	384 sq ft	14	10
12 × 12 ft	8 ft	492 sq ft	17	12
12 × 14 ft	8 ft	548 sq ft	20	13
14 × 16 ft	8 ft	668 sq ft	24	17
12 × 20 ft	8 ft	716 sq ft	26	17
16 × 20 ft	9 ft	932 sq ft	33	23
20 × 24 ft garage	9 ft	1,236 sq ft	43	29

National Gypsum's own estimating table, with no waste, gives 32 sheets of 4 × 8, 25 of 4 × 10 or 21 of 4 × 12 for 1,000 sq ft. The calculator returns the same counts when you enter 1,000 sq ft and 0% waste, which is a quick way to check it.

Joint compound, tape and screws per 1,000 sq ft

Finishing materials scale with the area of board, not the number of sheets. The figures below are National Gypsum's, from the materials estimating table in its ProForm construction guide and its product pages, for an ordinary level of finish: tape, a fill coat and a finish coat over the joints and the fasteners.

Board area	All-purpose ready-mix	Paper tape	Screws
100 sq ft	12 to 14 lb, 1 gal	35 to 38 ft	about 90
500 sq ft	62 to 70 lb, 4.5 gal	175 to 188 ft	about 390
1,000 sq ft	123 to 140 lb, 9 gal	350 to 375 ft	about 768
1,500 sq ft	184 to 210 lb, 13.5 gal	525 to 563 ft	about 1,128

The estimating table rounds tape to 350 ft per 1,000 sq ft; the tape's own product page says about 375 ft. The calculator uses 375 so you are not short. USG's figure for its ready-mix is about two 4.5 gal pails per 1,000 sq ft, which is the same 9 gal.

Compound comes in 4.5 gal pails and 3.5 gal cartons of ready-mix, or in bags of setting-type powder. Lightweight ready-mix weighs less per gallon, so buy by the gallon, not the pound.
Tape comes in 75, 250 and 500 ft rolls. The calculator counts 250 ft rolls.
Screws are a count from the same table. Ceilings, fire-rated walls and some framing call for closer spacing, so follow the plans and the board maker's fastening schedule.

Corner bead, a skim coat for a level 5 finish, texture and primer are extra and are not in the count.

Worked examples

A 12 × 12 bedroom, 8 ft walls, one door, one window, ceiling included, 4 × 8 sheets, 10% waste.

Walls: 2 × (12 + 12) × 8 = 384 sq ft, less 21 for the door and 15 for the window = 348 sq ft.
Ceiling: 12 × 12 = 144 sq ft. Area to finish: 492 sq ft.
Wall sheets: 348 × 1.10 ÷ 32 = 11.96, so 12. Ceiling sheets: 144 × 1.10 ÷ 32 = 4.95, so 5. Total 17 sheets.
Compound: 492 ÷ 1,000 × 9 = 4.4 gal, one 4.5 gal pail (61 to 69 lb).
Tape: 492 ÷ 1,000 × 375 = 185 ft, one 250 ft roll. Screws: 492 ÷ 1,000 × 768 = 378.

A basement rec room, 16 × 20 ft, 9 ft walls, 4 × 12 sheets. Walls 2 × 36 × 9 = 648, less one door and one window = 612 sq ft. Ceiling 320 sq ft. With 10% waste: 612 × 1.1 ÷ 48 = 14.03, so 15 wall sheets, and 320 × 1.1 ÷ 48 = 7.33, so 8 ceiling sheets. 23 sheets of 4 × 12 against 33 of 4 × 8, with fewer joints to finish.

A whole-house check. 1,000 sq ft of board at 0% waste is 32 sheets of 4 × 8, 9 gal of compound, 375 ft of tape and 768 screws. Those are the manufacturer's own numbers, so if your take-off for a bigger job lands far from them per 1,000 sq ft, recheck the measurements.

Choosing a sheet size

The right sheet is the longest one you can get into the room and lift into place:

4 × 8 ft (32 sq ft). Fits in any truck and up any stair. The default for small rooms, closets, patches and one-person jobs.
4 × 10 ft (40 sq ft). Suits walls about 10 or 20 ft long, and the extra length cuts the number of butt joints.
4 × 12 ft (48 sq ft). The fastest coverage on long walls and ceilings and the fewest joints, but heavy and awkward. Needs two people or a lift for ceilings.
Other sizes. Some makers sell 4 × 9 and 54 in wide board for 9 ft walls. For those, use the total area mode and divide by the sheet's own area.

Fewer joints matter more than fewer sheets. Butt joints, where two factory-cut ends meet, have no taper and take the most compound and skill to hide. Longer sheets put the joints where you choose them, or eliminate them.

Thickness does not change the count, but it changes what you order: 1/2 in for most walls, 5/8 in for ceilings on wide framing and for fire-rated walls such as between a garage and the house, and moisture- and mold-resistant board in bathrooms and basements. Check the plans and the local code.

From take-off to a price

The count is the first half of the quote. To turn it into a price:

Price each material at your supplier: sheets by size and type, compound by the pail, tape by the roll, screws by the box, plus corner bead and any texture.
Price the labor by the square foot of board or by the hour. Hanging and finishing are often priced separately, and ceilings and tall walls take longer than walls at arm's height.
Add delivery, stocking and haul-away of scraps.

"Save as an estimate in Koira" carries the sheets, compound, tape and a hang-and-finish line by the square foot into a Koira estimate, where you add your own prices and send it. For your hourly rate, see the labor rate calculator, and for the markup on materials, the markup calculator.

Last checked October 8, 2026. More for your trade: how remodelers run on Koira.

FAQ

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

With 8 ft walls, one door, one window and the ceiling, the area is 492 sq ft. With 10% waste that is 17 sheets of 4 × 8 (12 for the walls and 5 for the ceiling) or 12 sheets of 4 × 12.

How do I calculate drywall square footage?

Add the room's length and width, double it, and multiply by the wall height. Take off 21 sq ft for each standard door and about 15 for each window, then add length × width for the ceiling.

How much joint compound do I need per sheet of drywall?

National Gypsum puts it at 9 gal per 1,000 sq ft, about 0.29 gal per 4 × 8 sheet. A 4.5 gal pail finishes about 500 sq ft, or 15 to 16 sheets of 4 × 8.

How much drywall tape do I need?

About 375 ft of paper tape per 1,000 sq ft of board, according to National Gypsum. A 250 ft roll covers about 670 sq ft.

How many screws per sheet of drywall?

National Gypsum's estimating table works out to about 768 screws per 1,000 sq ft, roughly 25 for a 4 × 8 sheet. Ceilings and fire-rated assemblies can need more; follow the fastening schedule on the plans.

How much extra drywall should I buy for waste?

Many hangers allow about 10%, more for rooms with many openings, angles or short wall sections. Use what your own jobs run. Enter 0% to see the bare count.

Is it better to use 4 × 8 or 4 × 12 drywall?

4 × 12 sheets cover 50% more and leave fewer joints to finish, so they are faster on long walls and ceilings. 4 × 8 sheets are easier to carry and fit where long sheets cannot go.

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