How much drywall for a 12x12 room?

A 12 ft × 12 ft room with 8 ft walls has a 48 ft perimeter, so the walls alone are 384 ft². Adding the ceiling — another 144 ft² — brings the total to 528 ft². With the usual ten per cent waste allowance that is 580.8 ft² to order, which comes to 19 sheets of 4 × 8 ft board, about 608 screws, 1 box of joint compound and 1 roll of tape.

What size drywall sheet should I use?

4 × 8 ft is the everyday default — light enough for one person to carry and hang, and sold everywhere. 4 × 10 ft and 4 × 12 ft sheets cover more per board, which means fewer joints to tape on a tall wall or a long run, but a full 4 × 12 ft sheet is heavy and awkward without a second pair of hands or a panel lift. On the 528 ft² room above, moving from 4 × 8 ft to 4 × 12 ft cuts the sheet count from 19 down to 13.

How many screws per sheet of drywall?

About 32 screws for one 4 × 8 ft sheet on framing set 16 in apart — roughly one screw per square foot of board, which is the field rule this calculator uses. That scales up with the sheet: a 4 × 12 ft sheet, at 48 ft², wants about 48 screws to keep the same spacing. At 300 standard 1-1/4 in screws to the pound, 19 sheets need about 608 screws, or 3 lb.

How much joint compound do I need?

A field rule of about 0.053 lb of mud per square foot of board covers the taping coat and two finish coats. For the 528 ft² room above that is 27.98 lb, which rounds up to 1 standard 61.7 lb (4.5 gal) box. A whole house runs into several boxes fast, so most crews order by the pallet rather than the box once the area passes a few rooms.

How much drywall tape do I need?

About 0.38 ft of joint tape per square foot of board — close to the trade rule of 380 ft per 1,000 ft². The 528 ft² room above needs 201 ft of tape, which is one 500 ft roll with plenty to spare, or one 250 ft roll plus a little more. Paper tape is the standard choice with regular joint compound; mesh tape needs a setting-type compound underneath to bond properly.

How do I estimate drywall for a whole house?

Room by room is the accurate way: work out each room's wall and ceiling area the same way as a single room and add the sheet counts together, since rooms rarely share the same sheet size or waste needs. As a rough whole-house rule of thumb, total drywall area runs two-and-a-half to three times the finished floor area once every wall and ceiling is counted — a useful sanity check on a room-by-room takeoff, but not a substitute for one.

4 × 8 ft is lighter, cheaper per sheet, and the size every yard stocks, but it needs the most joints — the 528 ft² room above takes 19 of them. 4 × 12 ft drops that to 13 sheets and cuts the taping work to match, but a single sheet covers 48 ft² of solid board that two people should carry. On a tall wall or a long hallway, fewer joints usually wins; on a cut-up room with lots of corners, the lighter 4 × 8 ft sheet is easier to work alone.

Construction

Drywall Calculator

Drywall need is wall area (perimeter × height) plus any ceiling, divided by sheet coverage after a waste allowance. Enter a room or a total area to get sheets, screws, joint compound and tape — or work backward from the sheets you already have.

Measurements

Enter the room dimensions — walls always count, ceiling is optional.

Room length

Room width

Wall height8 ft is the standard residential ceiling

Boarding the ceiling too

Sheet size

Ordering

Waste allowance10–15% is standard

Price per sheetBoard only — screws, mud and tape are separate

$/ sheet

Tape roll size

Sheets needed

2 × (12 ft + 12 ft) × 8 ft + ceiling

Area to board

528 ft²

With 10% waste

580.8 ft²

Finishing materials

Screws

608

3 lb

Joint compound

box · 28 lb

Joint tape

roll · 201 ft

Field estimates, all rounded up — see the reference tables below for the assumptions.

Board cost

$285

19 × $15.00 — screws, mud and tape extra

Try a job

No sign-up · Free

Sheets always round up. Screw, mud and tape figures are common field estimates, not exact takeoffs — always buy a little extra.

The basics

How a drywall order is worked out

Every drywall estimate starts as an area problem and ends as a shopping list. Get the square footage right and the sheet count, the screws, the mud and the tape all fall out of the same handful of field rules.

sheets = area ÷ coverage

Area first, then sheets

Find the total area to be boarded — walls plus ceiling if it’s being finished too — add a waste allowance for offcuts, then divide by how much one sheet covers. The answer always rounds up, because a fraction of a board still has to be bought whole.

528 ft² × 1.1 waste ÷ 32 ft² = 19 sheets

board is only half the job

The finishing materials scale with it

Screws, joint compound and tape are not guesses — each follows its own field rule tied to the square footage of board, not the sheet count. Under-ordering any of the three stalls the same job a short sheet count would.

608 screws · 1 box of mud · 1 roll of tape

Method

How to size a drywall job by hand

Four steps take a tape measure to a number you can read down the phone to a lumber yard.

1
Find the wall area
Multiply the room's perimeter — twice the sum of length and width — by the wall height. Doors and windows are usually left uncut from the total; the offcuts they produce are absorbed by the waste allowance below.
2 × (12 + 12) × 8 = 384 ft²
2
Add the ceiling, if it's being boarded
Multiply length by width for the ceiling area and add it in. Skip this step entirely for a wall-only patch or a room whose ceiling is already finished.
12 × 12 = 144 ft² · 384 + 144 = 528 ft²
3
Add waste, then divide by the sheet size
Add ten to fifteen per cent for offcuts, waste around doors and windows, and simple mistakes, then divide by the coverage of one sheet and round up.
528 × 1.1 = 580.8 ft² ÷ 32 = 19 sheets
4
Estimate screws, joint compound and tape
Screws scale with the sheet count, while joint compound and tape scale with the raw board area — not the order area, since waste offcuts still get taped and mudded once they land on the wall.
19 × 32 = 608 screws · 528 × 0.053 = 28 lb mud

Worked examples

The same room, three sheet sizes

A 12 ft × 12 ft bedroom, boarded three different ways. The area never changes — only the sheet count, the joints, and how heavy each board is to carry.

A 12 ft × 12 ft bedroom, 8 ft walls, ceiling included, boarded in 4 × 8 ft sheets

Given L = 12 ft, W = 12 ft, H = 8 ft, sheet = 4 ft × 8 ft

Perimeter: 2 × (12 + 12) = 48 ft

Wall area: 48 × 8 = 384 ft²

Ceiling: 12 × 12 = 144 ft² · total = 528 ft²

With 10% waste: 528 × 1.1 = 580.8 ft²

Sheets: 580.8 ÷ 32 = 18.15 → 19 sheets

19 sheets

608 screws (3 lb) · 1 box of mud (28 lb) · 1 roll of tape (201 ft)

The standard sheet everywhere — easiest to carry alone and to find at any yard, but it needs the most joints on a full room.

Where it shows up

Why the drywall count matters

framing to finish

New construction

Drywall is ordered against the framing plan before insulation is even closed in, so a short count means a stalled crew waiting on a second delivery mid-week.

patch, match, blend

Renovation and repair

A single water-damaged panel or a removed wall still needs the same area math — just at a smaller scale, where matching the existing sheet thickness matters more than the size.

unfinished to livable

Basement and garage finishing

These jobs often add a fire-rated or moisture-resistant sheet to the mix and involve boarding a ceiling that a bedroom renovation would skip, which is why the mode matters.

Reference

Sheet sizes and what one covers

Every sheet count on this page comes from these three coverage figures. Bigger sheets trade weight and awkwardness for fewer joints to tape and mud.

Sheet	Coverage	Screws (est.)	Mud per sheet	Tape per sheet
4 × 8 ft	32 ft²	32	1.7 lb	12.2 ft
4 × 10 ft	40 ft²	40	2.12 lb	15.2 ft
4 × 12 ft	48 ft²	48	2.54 lb	18.2 ft

Screw, mud and tape figures are the field estimates this calculator uses — 300 screws per lb, 0.053 lb of mud per ft², 0.38 ft of tape per ft².

Quick chart

Drywall for common room sizes

Wall area and sheet count for the room sizes people actually search, at a standard 8 ft ceiling, walls only, with 10% waste already included. Add the ceiling separately if it's being boarded too.

Wall area and sheet count for common room sizes at an 8 ft ceiling, in 4×8 and 4×12 sheets
Room	Wall area	4 × 8 ft sheets	4 × 12 ft sheets
8 × 8 ftSmall bathroom or closet	256 ft²	9	6
8 × 10 ftSmall bedroom	288 ft²	10	7
10 × 10 ftBedroom	320 ft²	11	8
10 × 12 ftBedroom, larger	352 ft²	13	9
12 × 12 ftStandard bedroom / home office	384 ft²	14	9
12 × 14 ftLiving room, small	416 ft²	15	10
12 × 16 ftLiving room	448 ft²	16	11
12 × 20 ftBasement rec room, narrow	512 ft²	18	12
14 × 16 ftLiving room, large	480 ft²	17	11
16 × 20 ftBasement rec room	576 ft²	20	14
20 × 20 ftGarage conversion	640 ft²	22	15
20 × 24 ftTwo-car garage interior	704 ft²	25	17
24 × 30 ftWhole basement	864 ft²	30	20

A 500 ft² basement wall run needs 12 sheets of 4 × 12 ft board at the same 10% waste allowance.

Choosing board

Which drywall type to order

The area math is identical for every type below — what changes is the core and facing, picked for moisture, fire code, or mold risk rather than square footage.

1/2 in, most walls & ceilings

Regular (white board)

Plain gypsum board with a paper facing. The default for dry, ordinary rooms — bedrooms, living rooms, hallways — wherever there is no moisture or fire code to design around.

bathrooms, laundry, kitchens

Moisture-resistant (green/purple board)

A wax-treated core resists water absorption better than regular board, but it is not waterproof — it still needs tile backer or cement board directly behind a shower or tub surround.

garages, shared walls, stairwells

Fire-rated (Type X / Type C)

A thicker core with glass fibers slows a fire's spread through the wall. Building codes require it between a garage and living space, and on shared walls in multi-family construction.

basements, high-humidity rooms

Mold-resistant

A fiberglass facing instead of paper gives mold and mildew nothing organic to feed on. Worth the upgrade in a basement or a room that runs consistently humid, even without direct water contact.

Glossary

Compound, tape and screws

The finishing materials come in more than one flavour, and picking the wrong pairing — mesh tape with plain all-purpose mud, say — is a common source of cracked joints months later.

All-purpose joint compound: Pre-mixed, easy to sand, and fine for both taping and finish coats on a typical residential job. The default choice unless a step below calls for something faster or harder.
Setting-type ("hot mud") compound: A powder mixed with water that hardens by a chemical reaction rather than drying, so a second coat can go on the same day. Favoured for the first taping coat and for patching, where speed and strength matter more than easy sanding.
Paper tape: Folds into a crisp corner and bonds into wet compound with almost no bubbling once it is properly embedded. The standard choice for inside corners and the choice most pros default to everywhere.
Mesh (fiberglass) tape: Self-adhesive and easier for a first-timer to place flat, but it needs setting-type compound underneath — all-purpose mud alone does not bond mesh tape as well and can crack.
Coarse-thread drywall screws: Sized 1-1/4 in for a single layer of 1/2 in board into wood studs; fine-thread screws are used instead over metal studs. Screws hold better than nails and are what every count on this page assumes.

Worth knowing

Rules worth remembering

Six facts that turn a drywall order from a guess into a decision.

always round sheets up

You cannot buy part of a board

Sheet counts are ceilings, never averages. Rounding down to save one sheet is how a hang day ends with a bare stud bay and the yard already closed.

mud and tape follow raw area

Waste offcuts still get finished

Screws scale with the sheet count you buy, but joint compound and tape scale with the board actually going up on the wall — so size them off the raw area, not the padded order quantity.

528 ft² of board still needs 28 lb of mud, even though the order was 580.8 ft²

10 to 15 per cent

Waste is not optional

Cut-outs for outlets and windows, a damaged corner, a measuring slip — a ten to fifteen per cent allowance absorbs the ordinary losses of an ordinary hang day.

fewer sheets, heavier lift

Sheet size is a trade-off

Bigger sheets mean fewer joints to tape, which is real time saved on the mud coats — but a full 4×12 sheet is a two-person carry in most stairwells and hallways.

mind the ceiling

Ceilings are easy to forget

A ceiling doubles as a fourth wall in the area math but is easy to leave out of a mental estimate — always confirm whether it is in scope before pricing the job.

screws over nails

Screws hold better and count cleaner

Coarse-thread screws into wood studs, fine-thread into metal — either way, a screw count scales predictably with sheet area in a way a mixed nail-and-screw job never does.

FAQ

Common questions

Add up the wall area — perimeter times height — and the ceiling if it's being boarded too, then multiply by 1.1 for a ten per cent waste allowance and divide by the coverage of one sheet, rounding up. A 12 ft × 12 ft room with 8 ft walls and the ceiling included works out to 384 + 144 = 528 ft², which needs 19 sheets of standard 4 × 8 ft board. Bigger sheets need fewer of them: the same room takes 15 4 × 10 ft sheets or 13 4 × 12 ft sheets.

Keep going

Related calculators

Keep reading