Drywall Calculator
Calculate the number of drywall sheets, profiles, screws, and insulation needed for your drywall project. Get accurate material calculations and cost estimates.
Accurate Drywall Material Calculation
Our drywall calculator helps you determine the exact number of sheets, profiles, screws, and optional insulation needed for your project. Simply enter your room dimensions, sheet size, profile spacing, and screws per sheet. The calculator will provide you with detailed material requirements and cost estimates including all material costs and labor fees.
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Cost Breakdown
How to Estimate Drywall for a Room
To work out drywall for a room, add up the wall and ceiling square footage, divide by the square footage of one sheet, and add about 10% for waste. A 4x8 sheet covers 32 square feet, a 4x12 covers 48. The calculator above does that plus the screws, the framing and the mud — but the arithmetic underneath is that simple, and it is worth knowing so you can sanity-check any number a tool gives you.
1. Measure the walls
Multiply the perimeter of the room by the ceiling height. For a 16 by 12 foot room with 8 foot ceilings that is (16+12) x 2 = 56 feet of perimeter, times 8 = 448 square feet of wall.
2. Add the ceiling
Length times width. The same room adds 16 x 12 = 192 square feet, for 640 total.
3. Subtract the big openings only
Take out doors and windows over about 20 square feet. Leave the small ones in — the offcuts around a small window rarely produce anything usable, so subtracting them just makes you short.
4. Divide by your sheet size
640 square feet at 32 square feet per 4x8 sheet is 20 sheets. At 4x12 it is 13.3, so 14. Bigger sheets mean fewer joints to tape, which is where the labour hours actually go.
5. Add waste
Add 10% on a straightforward rectangular room and 15% where there are lots of corners, niches or angled ceilings. That takes 20 sheets to 22.
6. Work out the rest from the sheet count
Roughly 32 screws per sheet, a pound of drywall screws per 8 to 10 sheets, 400 feet of tape and 3 to 4 gallons of joint compound per 1,000 square feet for a standard three-coat finish.
Worked Example: a 16 x 12 Bedroom
16 by 12 feet, 8 foot ceilings, one standard door, one 3x4 window. Half-inch board, 4x8 sheets, studs at 16 inches on centre.
| Item | Working | Result |
|---|---|---|
| Wall area | 56 ft perimeter x 8 ft | 448 sq ft |
| Ceiling area | 16 x 12 | 192 sq ft |
| Openings removed | door only — the window is under 20 sq ft | −21 sq ft |
| Net area | 448 + 192 − 21 | 619 sq ft |
| Sheets before waste | 619 ÷ 32 | 19.3 |
| Sheets with 10% waste | 19.3 x 1.10, rounded up | 22 sheets |
| Screws | 22 sheets x 32 | ~700 (2 lb box) |
| Joint compound | 619 sq ft, three coats | ~2.5 gallons |
| Tape | 619 sq ft | ~250 ft |
Drywall Sheet Sizes and Coverage
US standard sheets. Coverage is the sheet area before any waste allowance.
| Sheet size | Coverage | Typical use |
|---|---|---|
| 4 x 8 ft | 32 sq ft | Most common. Fits through doorways and up stairs. |
| 4 x 10 ft | 40 sq ft | 9 and 10 foot walls hung horizontally with fewer joints. |
| 4 x 12 ft | 48 sq ft | Long walls and ceilings. Fewest joints, two people to hang. |
| 4 x 9 ft | 36 sq ft | 9 foot ceilings hung vertically, no butt joints. |
Drywall Cost: Which Number Are You After?
Three different questions get asked with the same words, and they need three different tools. This page is the quantity one. Pick whichever of the others matches what you are actually pricing.
How much board, mud and screws to buy
That is this page. Room geometry in, sheets and consumables out, with a waste allowance you can set. Nothing is priced.
What it costs to hang and finish new board
Square footage and your own rates in, a cost per square foot out. That is the drywall cost calculator, and the mud on its own is the joint compound calculator.
What it costs to repair existing board
A different shape of question, because a small hole and a large one take the same sequence of visits. Repairs price from hours, trips and a minimum callout, which is what the drywall repair cost calculator does.
Where Estimates Go Wrong
Subtracting every window and door
The offcuts around a small opening are mostly unusable. Taking them off the total is how you end up two sheets short on a Friday afternoon.
Ordering the same waste percentage for every room
A plain rectangle wastes very little. A room with a tray ceiling, angled walls or a stairwell can waste a fifth of what you carry in.
Forgetting that sheet size changes the labour, not just the count
Twelve-foot sheets cut the number of butt joints hard, and butt joints are the slow, fussy part of taping. Fewer sheets can mean fewer hours as well as less material.
Drywall Calculator — Common Questions
What is drywall priced at per square foot?
Installation is genuinely a per-square-foot job, and the drywall cost calculator works it out from your board price, your compound, your screws and your hanging and finishing rates. Repair is not: a small hole and a large one take the same sequence of visits, so it prices from hours and a minimum callout instead. Use the repair calculator for that.
How many drywall sheets do I need for a 12x12 room?
With 8 foot ceilings, that is 384 square feet of wall plus 144 of ceiling, 528 total. At 32 square feet per 4x8 sheet that is 16.5 sheets, so 18 or 19 with waste.
How much drywall does a 4x8 sheet cover?
32 square feet. A 4x10 covers 40 and a 4x12 covers 48.
How much waste should I allow for drywall?
About 10% on straightforward rectangular rooms, 15% where there are many corners, angled ceilings or niches. Under 10% and you will be back at the supplier.
How many screws per sheet of drywall?
Around 32 for a 4x8 sheet on studs 16 inches on centre — perimeter screws every 8 inches, field screws every 12. That works out at roughly one pound of screws per 8 to 10 sheets.
How much joint compound do I need?
Roughly 3 to 4 gallons per 1,000 square feet of board for a standard three-coat finish, plus about 400 feet of tape over the same area.
The Other Calculators
All free, all the same idea: measurements in, quantities out, your own prices on top.
Concrete Calculator
Yardage, bags and cost for a slab, footing or pour, at your own rates, plus what actually drives the price of a concrete job beyond the ready-mix.
Open the calculator →Paint Calculator
Paint quantities and cost for walls and ceilings separately, in gallons, with coats and coverage accounted for, plus what decides an interior or exterior painting price.
Open the calculator →Tile Calculator
Tiles, boxes and grout for a floor or wall, with the waste allowance that saves the second trip, plus what tile installation costs per square foot and why the rate is not one number.
Open the calculator →Drywall Cost Calculator
Price a drywall job: board, compound, tape, screws, hanging and finishing labor, at your own rates, with the cost per square foot at the end.
Open the calculator →Concrete Cost Calculator
Price a slab: ready-mix, the short-load fee, gravel base, forms, rebar and finishing labor at your own rates, ending with the cost per square foot.
Open the calculator →CMU Block Calculator
Blocks, courses, mortar bags and reinforcement for a concrete block wall, with your own prices on top, plus what a block wall costs once the footing and the steel are counted.
Open the calculator →Brick Calculator
Bricks and mortar for a wall, by brick size and joint thickness, plus what a brick wall costs to build once the footing, the bond and the access are priced.
Open the calculator →Tile Cost Calculator
Price a tile job: tile, thinset, grout, trim, substrate prep and setting labor at your own rates, with the cost per square foot at the end.
Open the calculator →Painting Cost Calculator
Price a painting job: paint, primer, preparation hours, trim, access and sundries at your own rates, interior or exterior, per square foot.
Open the calculator →Drywall Repair Calculator
Price a drywall repair the way it is actually quoted: by repair type, hours, trips to the house and your minimum callout charge.
Open the calculator →Drywall Mud Calculator
How much joint compound and tape a job takes, by finish level, converted into the boxes, pails and bags you actually buy.
Open the calculator →Electrician Calculator
Wire length and cost for a circuit run, by conductor size and material, plus what decides the price of the job: open walls, the number of openings, and what the panel can take.
Open the calculator →Put This Calculator on Your Site
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Winning the Job Is the Other Half
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