How many sheets of drywall do I need?

Add up the length of every wall and multiply by the wall height to get the wall area. Add the ceiling (room length × width) if you are covering it too, and subtract large doors and windows. Multiply by 1.10 for waste and divide by the area of one sheet: 32 sq ft for 4 × 8, 40 for 4 × 10, 48 for 4 × 12. Round up. A 12 × 12 ft room with 8 ft walls and its ceiling is 528 sq ft, which is 19 sheets of 4 × 8 with 10% waste.

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

With 8 ft walls, the four walls are 384 sq ft: 14 sheets of 4 × 8 with 10% waste. Adding the 144 sq ft ceiling makes 528 sq ft and 19 sheets. The table on this page lists other common room sizes.

Should I subtract doors and windows?

Subtract large openings such as doors, wide windows and pass-throughs; the calculator takes each one you add off the wall area. Many installers leave small windows in, because the board is often hung over the opening and cut out, and the offcut is rarely usable. When in doubt, leave an opening in: a spare sheet is cheaper than a second trip.

Is 4 × 8 or 4 × 12 drywall better?

Longer sheets cover a wall with fewer joints, so there is less taping and sanding, and 4 × 12 sheets run the full length of a 12 ft wall without a butt joint. They are also heavy (a 1/2 in 4 × 12 sheet weighs well over 50 lb) and hard to get up stairs or onto a ceiling alone. 4 × 8 sheets are the easiest to carry and hang alone. The calculator counts sheets for any of the three sizes; its compound and tape figures are per sq ft, so they do not change with the sheet size.

How much joint compound do I need for drywall?

USG lists 9.4 gal of its lightweight ready-mixed compound per 1,000 sq ft of board (its all-purpose literature rounds this to about 9 to 10 gal). That is about 0.3 gal per 4 × 8 sheet, or one 4.5 gal pail for every 450 sq ft or so. The 528 sq ft room above needs about 5 gal: 2 pails. It is an estimate: extra coats, lots of inside corners or a textured finish use more.

How much drywall tape do I need?

About 370 ft of paper tape per 1,000 sq ft of board, per USG, or about 11.8 ft per 4 × 8 sheet. Rolls commonly come in 250 and 500 ft; this calculator counts 250 ft rolls (the joint compound calculator lets you pick 500 ft). The 12 × 12 ft room with its ceiling needs about 195 ft, so 1 roll.

How many screws per sheet of drywall?

USG’s handbook estimates about 1,000 screws per 1,000 sq ft of board with framing 16 in on center, and about 850 at 24 in: roughly 32 and 27 per 4 × 8 sheet. A 5 lb box of #6 × 1-1/4 in coarse-thread screws holds about 1,190, so 1 lb (about 238 screws) does roughly 7 sheets at 16 in. Ceilings are often fastened closer, so buy a little extra for them.

How much extra drywall should I buy?

Add about 10% for a plain rectangular room, and about 15% for rooms with many windows, angled walls, soffits or short wall sections, where more of each sheet ends up as offcuts. A spare sheet is also handy for repairs later.

Drywall Calculator: How Many Sheets Do I Need?

Sheets of drywall = wall and ceiling area × 1.10 ÷ the area of one sheet (32 sq ft for 4 × 8), rounded up. A 12 × 12 ft room with 8 ft walls has 48 ft × 8 ft = 384 sq ft of wall plus a 144 sq ft ceiling, 528 sq ft in all: 19 sheets of 4 × 8 drywall with 10% waste (14 for the walls alone). Finishing it takes about 5 gal of joint compound (2 pails of 4.5 gal), 195 ft of paper tape (1 roll of 250 ft) and 528 screws (about 2.2 lb). The supplies are rules of thumb from USG’s published figures.

Figures based on the sources listed belowUpdated 2026-09-29How we calculate

Total wall length

Wall height

Waste allowance

Standard (+10%)Many openings, angles or short walls (+15%)Custom

Sheet sizeLonger sheets leave fewer joints to tape but are heavier to carry and hang. A metric 1.2 × 2.4 m board is close to 4 × 8 ft.

Ceiling area (sq ft)

Room length × width if you are hanging the ceiling too. Leave 0 for walls only.

Stud or joist spacingSets the screw count: wider framing takes fewer screws.

Price per sheet (optional)

Buy 19 sheets

528 sq ft + 10% waste = 580.80 sq ft

Joint compound (4.5 gal pails): 2 pails (≈ 5 gal)
Paper joint tape (250 ft rolls): 1 roll (≈ 195.4 ft)
Drywall screws: 528 screws (≈ 2.2 lb)

Low

$228.00

Expected

$304.00

High

$418.00

Includes 52.80 sq ft waste

How this number is calculated

528 sq ft + 10% waste = 580.80 sq ft ÷ 32 sq ft per sheet = 19 sheets

Next step in your project

Primer Calculator
Prime the new drywall before painting. Opens with your 48 × 8 ft filled in.
Room Paint Calculator
Paint for the same walls. Opens with your 48 × 8 ft filled in.

Shopping list

Drywall screws (#6 × 1-1/4 in, coarse thread)
All-purpose joint compound
Paper drywall joint tape
Drywall taping knives (6, 10 and 12 in)
Drywall T-square
Drywall screw setter bit
Corner bead
Drywall sanding sponge

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How many sheets of drywall for a room

Worked by this calculator: 8 ft walls, no openings subtracted, 10% waste, rounded up to whole sheets. Subtract doors and windows in the calculator for a closer count.
Room	Wall area (sq ft)	4 × 8 sheets, walls	Walls + ceiling (sq ft)	4 × 8 sheets, walls + ceiling	4 × 12 sheets, walls + ceiling
10 × 10 ft	320	11	420	15	10
10 × 12 ft	352	13	472	17	11
12 × 12 ft	384	14	528	19	13
12 × 14 ft	416	15	584	21	14
14 × 16 ft	480	17	704	25	17
16 × 20 ft	576	20	896	31	21

Joint compound, tape and screws per 1,000 sq ft (rules of thumb)

Estimates from USG’s published figures (see sources), the same rates the calculator uses. Screws are weighed at about 238 per lb (#6 × 1-1/4 in coarse thread). More corners, more coats or a heavier hand mean more compound.
Supply	Per 1,000 sq ft of board	Per 4 × 8 sheet
Ready-mixed joint compound	9.4 gal (2.1 pails of 4.5 gal)	about 0.3 gal
Paper joint tape	about 370 ft (1.5 rolls of 250 ft)	about 11.8 ft
Screws, framing 16 in on center	about 1,000 (4.2 lb)	about 32
Screws, framing 24 in on center	about 850 (3.6 lb)	about 27

Methodology & assumptions

Wall area is the total length of the walls times the wall height (for a rectangular room, 2 × (length + width) × height), plus the ceiling area if you enter one, minus the doors and windows you add. The area is multiplied by 1 plus the waste allowance (10%, or 15% for rooms with many openings, angles or short walls) and divided by the area of one sheet: 32 sq ft for 4 × 8, 40 for 4 × 10 and 48 for 4 × 12, rounded up to whole sheets. The finishing supplies are estimates worked from the net board area (after openings, before waste) with rules of thumb from USG’s product literature: 9.4 gal of ready-mixed joint compound and 370 ft of paper tape per 1,000 sq ft of board (the same rates as the joint compound calculator, which also lets you pick 500 ft tape rolls), and about 1,000 screws per 1,000 sq ft with framing 16 in on center (850 at 24 in). Screws are weighed at about 238 per lb, the count in a 5 lb box of #6 × 1-1/4 in coarse-thread drywall screws. Real use depends on the number of joints and corners, how thick you apply compound and how many coats you use, so treat them as a starting shopping list. The metric toggle shows lengths in m and the ceiling in m²; sheet sizes stay in feet as sold in the US (a 1.2 × 2.4 m board is close to 4 × 8 ft).

USG, Sheetrock Brand All Purpose Joint Compound submittal sheet: ready-mixed all-purpose compound, roughly 9 to 10 gal per 1,000 sq ft of board
USG, Sheetrock Brand Plus 3 Joint Compound submittal sheet: about 9.4 gal per 1,000 sq ft of board
USG, Sheetrock Brand Paper Joint Tape: about 370 ft per 1,000 sq ft of board
USG, The Gypsum Construction Handbook: about 1,000 screws per 1,000 sq ft of board at 16 in on center, 850 at 24 in
Retail 5 lb boxes of #6 × 1-1/4 in coarse-thread drywall screws: about 1,190 screws (about 238 per lb)
Typical US retail prices for 1/2 in drywall sheets, 2026 (estimate)

How to calculate how much drywall you need

Add up the wall lengths. Measure each wall and add them together. For a rectangular room that is 2 × (length + width); a 12 × 12 ft room has 48 ft of wall.
Enter the wall height and the ceiling. Enter the wall height; the calculator multiplies it by the wall length. If you are covering the ceiling too, enter its area (room length × width).
Subtract doors and windows. Add each large door or window as an opening so its area comes off the total. Small openings can stay in.
Pick a sheet size and waste. Choose 4 × 8, 4 × 10 or 4 × 12 sheets and a waste allowance: 10% for a plain room, 15% for one with many openings or angles.
Divide by the sheet area and round up. Divide the area with waste by 32, 40 or 48 sq ft and round up to whole sheets. The calculator also estimates joint compound, tape and screws from the board area.

Worked examples

Project	Result
12 × 12 ft room, 8 ft walls, with ceiling, 4 × 8 sheets	528 sq ft + 10% waste ≈ 580.8 sq ft → 19 sheets
12 × 14 ft room, 8 ft walls only, minus a door (3 × 6.75 ft) and a window (3 × 4 ft)	383.75 sq ft + 10% waste ≈ 422.13 sq ft → 14 sheets
14 × 16 ft room, 9 ft walls, with ceiling, 4 × 12 sheets	764 sq ft + 10% waste ≈ 840.4 sq ft → 18 sheets
20 × 30 ft basement, 8 ft walls only, many openings (15%), framing 24 in on center	800 sq ft + 15% waste ≈ 920 sq ft → 29 sheets

Frequently asked questions

How many sheets of drywall do I need?: Add up the length of every wall and multiply by the wall height to get the wall area. Add the ceiling (room length × width) if you are covering it too, and subtract large doors and windows. Multiply by 1.10 for waste and divide by the area of one sheet: 32 sq ft for 4 × 8, 40 for 4 × 10, 48 for 4 × 12. Round up. A 12 × 12 ft room with 8 ft walls and its ceiling is 528 sq ft, which is 19 sheets of 4 × 8 with 10% waste.
How many sheets of drywall for a 12 × 12 room?: With 8 ft walls, the four walls are 384 sq ft: 14 sheets of 4 × 8 with 10% waste. Adding the 144 sq ft ceiling makes 528 sq ft and 19 sheets. The table on this page lists other common room sizes.
Should I subtract doors and windows?: Subtract large openings such as doors, wide windows and pass-throughs; the calculator takes each one you add off the wall area. Many installers leave small windows in, because the board is often hung over the opening and cut out, and the offcut is rarely usable. When in doubt, leave an opening in: a spare sheet is cheaper than a second trip.
Is 4 × 8 or 4 × 12 drywall better?: Longer sheets cover a wall with fewer joints, so there is less taping and sanding, and 4 × 12 sheets run the full length of a 12 ft wall without a butt joint. They are also heavy (a 1/2 in 4 × 12 sheet weighs well over 50 lb) and hard to get up stairs or onto a ceiling alone. 4 × 8 sheets are the easiest to carry and hang alone. The calculator counts sheets for any of the three sizes; its compound and tape figures are per sq ft, so they do not change with the sheet size.
How much joint compound do I need for drywall?: USG lists 9.4 gal of its lightweight ready-mixed compound per 1,000 sq ft of board (its all-purpose literature rounds this to about 9 to 10 gal). That is about 0.3 gal per 4 × 8 sheet, or one 4.5 gal pail for every 450 sq ft or so. The 528 sq ft room above needs about 5 gal: 2 pails. It is an estimate: extra coats, lots of inside corners or a textured finish use more.
How much drywall tape do I need?: About 370 ft of paper tape per 1,000 sq ft of board, per USG, or about 11.8 ft per 4 × 8 sheet. Rolls commonly come in 250 and 500 ft; this calculator counts 250 ft rolls (the joint compound calculator lets you pick 500 ft). The 12 × 12 ft room with its ceiling needs about 195 ft, so 1 roll.
How many screws per sheet of drywall?: USG’s handbook estimates about 1,000 screws per 1,000 sq ft of board with framing 16 in on center, and about 850 at 24 in: roughly 32 and 27 per 4 × 8 sheet. A 5 lb box of #6 × 1-1/4 in coarse-thread screws holds about 1,190, so 1 lb (about 238 screws) does roughly 7 sheets at 16 in. Ceilings are often fastened closer, so buy a little extra for them.
How much extra drywall should I buy?: Add about 10% for a plain rectangular room, and about 15% for rooms with many windows, angled walls, soffits or short wall sections, where more of each sheet ends up as offcuts. A spare sheet is also handy for repairs later.

Handy tools

Feet and Inches Calculator: Add up wall lengths measured in feet, inches and fractions, and get decimal feet for the fields above.
Decimal to Fraction Converter: Turn a decimal-inch cut such as 47.3125 into the nearest 1/16 on a tape measure when you trim a sheet to height.