Drywall Calculator
Sheets, screws, joint tape, and joint compound for any room. Built for drywall contractors and homeowners pricing a hang and finish job.
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Multiply each wall length by ceiling height, sum them up, then add the ceiling area. Subtract about 20 sq ft per standard door and 15 sq ft per window if you want to be precise.
1/2 inch sheets are usually $14 to $20. 5/8 inch and moisture-resistant boards cost more.
Your result
- Sheet costAt $16.00 per sheet
- $336.00
- Drywall screwsA 5 lb box of #6 x 1-1/4" screws has about 1,400 to 1,600 screws.
- 672screws
- Joint tapePaper tape comes in 250 ft and 500 ft rolls.
- 300linear ft
- Joint compoundCovers taping plus two finish coats.
- 15-gallon buckets
Example. A 12 ft by 14 ft room with 8 ft ceilings has about 584 sq ft of drywall surface. With 10% waste and 4x8 sheets, you need 21 sheets. At $16 each, that is $336.
Save this as a free estimateHow to measure drywall area
Measure each wall (length × ceiling height), add them together, then add the ceiling area (length × width of the room). For a 12 × 14 ft room with 8 ft ceilings:
- Two 12 ft walls: 192 sq ft
- Two 14 ft walls: 224 sq ft
- Ceiling: 168 sq ft
- Total: 584 sq ft
Subtract 20 sq ft per standard door and 15 sq ft per window if you want a tighter count. Otherwise skip the subtraction and let the 10 percent waste factor cover it.
Drywall sheet sizes
The standard 4 × 8 ft sheet is what most home centers stock and what fits in a pickup. Bigger sheets cut your seam count, which speeds up taping.
- 4 × 8 ft (32 sq ft)Two people can carry one.Default
- 4 × 9 ft (36 sq ft)For 9 ft ceilings, runs vertically.Tall walls
- 4 × 10 ft (40 sq ft)Reduces seams.Long walls
- 4 × 12 ft (48 sq ft)Fewer seams but awkward to handle.Pros only
Thickness matters too. 1/2 inch is standard for walls and ceilings. 5/8 inch is for fire-rated walls (between living space and an attached garage, for example) and ceilings under 24-inch joist spacing. Moisture-resistant green board is for bathrooms but is not waterproof. Cement board goes behind tile in showers.
Drywall pricing
For materials alone, a typical 12 ft by 14 ft room costs $330 to $450 in drywall, mud, tape, and screws. Add $1.50 to $3.50 per square foot for labor if you hire it out. A pro finisher gets a smoother surface than most DIYers because of practice with the trowel.
Materials beyond the drywall sheets
The sheets are about 60 percent of the materials cost. The rest:
- Drywall screws: 32 screws per 4x8 sheet on stud framing, or 56 per sheet on metal stud framing. A 5 lb box of #6 x 1-1/4 inch screws ($10 to $15) has about 1,400 to 1,600 screws.
- Joint compound (mud): one 5-gallon bucket of all-purpose joint compound (about $18) covers roughly 100 to 200 sq ft of wall through taping and two finish coats, depending on how thick you apply. Buy more for textured ceilings.
- Joint tape: paper tape (250 ft for $4) is stronger than fiberglass mesh. Both work. Paper is the pro choice for flat seams.
- Corner bead: $1.50 to $3 per 8 ft length. Count one per outside corner.
- Sanding pole and screen: $25 to $40 one-time.
- Mud pan and 6 inch, 10 inch, and 12 inch knives: $30 to $60 if you do not have them.
Pricing the job for a client
Materials are usually 40 to 50 percent of the bill. To turn this into a client estimate, add labor (hang, tape, finish coats, sand), waste disposal, and your contractor markup. The markup calculator handles the cost-to-price math. The drywall estimate template gives you a one-page bill format, and the invoice template hub has formats for handing the final invoice to the client.
Painting after the hang-and-finish? Run the paint calculator next.
How many sheets of drywall do I need for a 12x12 room?
A 12 ft by 12 ft room with 8 ft ceilings has 528 sq ft of walls and ceiling. At 4x8 sheets (32 sq ft each), that is 16.5 sheets before waste. Round up to 18 sheets to cover the 10 percent waste factor for the cuts around outlets, windows, and corners.
How much drywall mud do I need per sheet?
About 0.03 to 0.05 gallons of all-purpose joint compound per square foot of drywall through taping and two finish coats. A standard 4x8 sheet (32 sq ft) takes about 1 to 1.5 gallons. A 5-gallon bucket finishes 100 to 200 sq ft (roughly 3 to 5 sheets). For a 12x14 room with around 549 sq ft of drywall, plan on 17 to 27 gallons total, which is about 4 to 5 buckets.
What thickness drywall should I use?
Use 1/2 inch drywall for most interior walls and ceilings. Use 5/8 inch where code requires fire rating (between living space and an attached garage, or on ceilings with joists spaced more than 16 inches apart). Use moisture-resistant board (green board) on bathroom walls. Use cement board, not drywall, behind tile in showers.
Send this drywall estimate to your client
InvoiceOwl drops your sheet count, screws, mud, and total cost into a branded estimate. Email it, get e-signed, then convert to invoice in one tap.
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