# Drywall calculator

> 14′ × 12′ room: 21 sheets (4×8) for 533 sq ft of walls and ceiling, 2 pails of joint compound, and the tape and screws. Sheets, screws, tape, compound and corner bead for walls and ceilings, finished to the level you want.

## What to buy (14′ × 12′ room)

Every line shows the quantity to buy and how StudSheet got it: the spacing, the waste and the package size, so you can check it before the supply house or the quote.

| Buy | Material | How StudSheet counts it | What it is for |
|---|---|---|---|
| **15 sheets** | Drywall ½″ (4×8 sheets) | Walls, laid out wall by wall: 4 walls (2 × 14′ and 2 × 12′), 2 rows across the studs: 8 full + 6 cut for the row ends = 14. Offcuts are reused where they fit; doors and windows are cut out of full sheets. + 1 spare for breakage (about 5%). Covers 365 sq ft. | Standard gypsum board for walls. |
| **6 sheets** | Lightweight drywall ½″ (4×8 sheets) | Ceiling: 3 rows across the joists, 14′ long: 3 full + 3 cut for the row ends = 6. Covers 168 sq ft. | About a quarter lighter than regular board and sag-resistant on ceilings — the usual pick overhead. |
| **≈693 screws (3 lb)** | Drywall screws, coarse thread (1¼″ coarse thread) | 15 wall sheets × 28 (one every 16″ on each stud) + 6 ceiling sheets × 35 (one every 12″ on each joist) + 10% for drops and strips. ½″ board takes 1¼″ screws — at least ⅝″ into the wood (IRC R702.3.6). About 250 per lb. | Coarse thread bites wood studs. |
| **2 pails** | All-purpose joint compound (4.5-gal pail (≈62 lb)) | 533 sq ft of board × 10 gal per 1,000 sq ft for Level 4 (tape + 2 coats) = 5.3 gal (USG: about 9.4–10 gal per 1,000 sq ft for a three-coat job). | Premixed “mud” for taping and finish coats. |
| **1 roll** | Paper joint tape (250 ft roll) | 197 ft: about 370 ft per 1,000 sq ft of board (USG), seams and inside corners. | Bedded in mud over seams and inside corners. |
| **2 gallons** | Drywall primer (PVA) (1 coat) | 533 sq ft ÷ 300 sq ft/gal = 1.78 gal. Seals the paper and the compound so the paint dries evenly. | Seals new drywall so the paint dries evenly. |
| **1 pack** | Drywall sanding screens (120–150 grit, 10-pack) | About one pack per 600 sq ft of board: a light pass after each coat dries, never through to the paper. | Open-mesh sheets for a pole or hand sander. They don’t clog like paper. |

### In Canada (4.27 m × 3.66 m room)

Set to Canada, the Sheet works the job out again for Ontario: metric sizes, bag sizes, the frost depth and the code notes. It doesn't just convert feet to meters. The first lines:

- **15 sheets, Drywall 13 mm:** Walls, laid out wall by wall: 4 walls (2 × 4.27 m and 2 × 3.66 m), 2 rows across the studs: 8 full + 6 cut for the row ends = 14. Offcuts are reused where they fit; doors and windows are cut out of full sheets. + 1 spare for breakage (about 5%). Covers 33.9 m².
- **6 sheets, Lightweight drywall 13 mm:** Ceiling: 3 rows across the joists, 4.27 m long: 3 full + 3 cut for the row ends = 6. Covers 15.6 m².
- **≈693 screws (1.4 kg), Drywall screws, coarse thread:** 15 wall sheets × 28 (one every 400 mm on each stud) + 6 ceiling sheets × 35 (one every 300 mm on each joist) + 10% for drops and strips. 13 mm board takes 32 mm screws — at least 15 mm into the wood (NBC 9.29.5.5). About 550 per kg.
- **2 pails, All-purpose joint compound:** 49.5 m² of board × 0.41 L per m² for Level 4 (tape + 2 coats) = 20.2 L (USG: about 0.38–0.41 L per m² for a three-coat job).
- **1 roll, Paper joint tape:** 60.11 m: about 1.2 m per m² of board (USG), seams and inside corners.
- **2 × 3.78 L, Drywall primer (PVA):** 49.5 m² ÷ 27.9 m² per 3.78 L = 6.7 L. Seals the paper and the compound so the paint dries evenly.

## The steps, in order

> **DIY OK: you can do this yourself with standard tools.** About 28–42 hours of work for this example.

1. Before you hang: framing straight and flush (plane or shim high and low studs), blocking at every inside corner and ceiling edge, insulation in, and any framing, wiring, plumbing and insulation inspections signed off.
2. Mark every joist on the top of the walls and every stud on the floor, and measure the outlet boxes and pipes you’ll cut around.
3. Hang drywall on the ceiling first: sheets across the joists, ends staggered and on a joist, screws 12″ apart — a rented drywall lift or a helper holds the sheet.
4. Hang drywall on the walls across the studs: top row tight to the ceiling, bottom row ½″ off the floor; end joints on a stud, staggered row to row and never in line with a door or window edge; screws 16″ apart.
5. Cut out the boxes and the doors and windows you hung over (jab saw or spiral saw), and add a screw wherever an edge isn’t held.
6. Tape coat: fill gaps over ⅛″ with setting-type compound first, then bed paper tape in compound on every seam and inside corner, wipe it tight, and cover the screw heads.
7. Fill coat: a wider coat of premixed compound over the flat seams, the butt joints and the screw heads.
8. Finish coat: a thin coat, feathered wider than the last, on the same seams and screws, plus one coat on the inside corners.
9. Sand: a light pass with a 120–150 grit screen or sponge — never into the paper — then check every joint with a work light held flat to the wall.
10. Prime: one coat of PVA drywall primer before paint.

## Tools (28)

Must-have tools first, then the ones that help and the ones to rent for the day.

| Tool | Need | Why |
|---|---|---|
| **Tape measure (25 ft)** | **Must have** | The red boxes every 16″ on the blade are stud spacing. |
| **Carpenter's pencil** | **Must have** | Flat, doesn't roll away, marks rough lumber. |
| **Stud finder** | **Must have** | Find and mark every stud and joist before the sheet hides them |
| **Chalk line** | **Must have** | Snap joist and stud lines to screw along |
| **Utility knife + blades** | **Must have** | Score and snap; swap blades often |
| **Drywall T-square** | **Must have** | Guides straight, full-width drywall cuts. |
| **Drywall rasp** | **Must have** | Shave a tight edge instead of forcing the sheet |
| **Drywall jab saw** | **Must have** | Outlet boxes and pipe holes |
| **Cordless drill/driver** | **Must have** | With a dimpler bit, or use a screw gun |
| **Drywall dimpler bit (or screw gun)** | **Must have** | Sets each screw just below the paper |
| **Mud pan** | **Must have** | Holds joint compound while you work. |
| **6″ taping knife** | **Must have** | Tape coat and screw heads |
| **10–12″ taping knife** | **Must have** | Wide, thin later coats |
| **Inside-corner trowel** | Good to have | Inside corners in one pass |
| **½″ drill + mixing paddle** | Good to have | Remix premixed compound smooth (a splash of water) |
| **Sanding sponges** | **Must have** | Low-dust sanding for mud, patches and scuffing old paint. |
| **Pole sander** | **Must have** | Reach high joints from the floor |
| **Work light** | **Must have** | Held flat to the wall, it shows every ridge before you paint |
| **N95 dust masks** | **Must have** | Cutting and sanding dust |
| **Safety glasses** | **Must have** | Every cut, every nail, every time. |
| **Shop vac** | **Must have** | Dust and scraps |
| **Step ladder (6 ft)** | **Must have** | Reaches 8-ft ceilings safely. |
| **Drywall lift** | Rent | Holds a full sheet against the ceiling while you screw it off |
| **Spiral saw (drywall cut-out tool)** | Good to have | Cuts around boxes and windows after the sheet is up |
| **Auto-feed screw gun** | Good to have | Collated screws to the right depth, fast |
| **Panel foot lifter** | Good to have | Lifts the bottom row tight to the one above |
| **Drywall power sander + vacuum** | Good to have | Sands with the dust pulled into a vacuum |
| **Dust-barrier poles** | Good to have | Plastic walls floor to ceiling around the work |

## Mistakes and how the math works

### Mistakes that cost a callback or a second trip

- **End joints lined up:** Butt joints stacked in a line, or on the jamb line of a door or window, crack. Stagger them at least a stud apart and lap sheets over the corners of openings.
- **Screws too deep or proud:** Torn paper loses its hold; a proud head shows through the compound. A dimpler bit sets them just below the surface.
- **Thick coats of premixed compound:** They shrink, crack and take days to dry. Thin coats, feathered wide; fill deep gaps with setting-type compound first.
- **Drywall touching the floor:** It wicks water. Hold the bottom row ½″ up; the baseboard covers the gap.
- **Sanding through the paper:** Fuzzy paper shows through paint. Sand lightly with 120–150 grit and prime before you judge the finish.

### What the calculator assumes

- Sheets counted wall by wall: full rows across the studs (or columns up and down), end joints on framing (a 4×10 on 16″ framing is trimmed to 112″), a ripped strip where the height doesn’t divide (up to 1″ is left at the floor), offcuts reused for row ends where they fit.
- Doors (21 sq ft) and windows (15 sq ft) come out of the area for compound and primer but not out of the sheet count: they’re cut out of full sheets. Big openings (a garage door, an archway, a tub alcove) take whole sheets off.
- Ceiling sheets run across the joists, along the room’s length (joists usually span the short way).
- Screws (IRC Table R702.3.5): walls 16″ apart on 16″ framing, 12″ on 24″ framing; ceilings 12″; at least ⅝″ into the wood (R702.3.6), ⅜″ in from the edges.
- Finish levels (GA-214): Level 2 tape coat only; Level 3 tape + 1 coat; Level 4 tape + 2 coats (inside corners 1); Level 5 adds a skim coat over everything.
- Compound ≈ 10 gal per 1,000 sq ft for Level 4 (USG: 9.4–10), scaled by level; paper tape ≈ 370 ft per 1,000 sq ft (USG).
- Primer: one coat at 300 sq ft/gal.
- Cold weather: keep the space at 55 °F or warmer while you tape and until the compound is dry (USG).

## Code, permits and safety

The Sheet sets its code notes for the job's state or province. These are New Jersey's and Ontario's; the [code reference](https://studsheet.com/codes) has more. Always confirm with your building department.

- **Permits:** a job like this usually needs none, but towns set their own rules. Ask your building department if you're not sure.

## Questions

### What materials do I need to hang and finish drywall?

For the worked example, a 14′ × 12′ room, the Sheet counts 7 lines with waste included, starting with drywall ½″ (15 sheets), lightweight drywall ½″ (6 sheets), drywall screws, coarse thread (≈693 screws (3 lb)), all-purpose joint compound (2 pails). Each line's math is in the table above. Put in your own sizes in the [drywall calculator](https://app.studsheet.com/p/drywall) and every line is counted again.

### How long does it take to hang and finish drywall, and can I do it myself?

About 28 to 42 hours for the worked example, in 10 steps. StudSheet stamps it **DIY OK**: you can do this.

### What tools do I need to hang and finish drywall?

28 in all. The must-haves start with tape measure (25 ft), carpenter's pencil, stud finder, chalk line, utility knife + blades, drywall t-square. On the Sheet you mark each one as owned, to buy or to rent.

## Ask about it

Stuck while you hang and finish drywall? Ask in the [Drywall group](https://studsheet.com/forum/drywall) of the StudSheet community with this Sheet attached. Homeowners who've done it and verified pros answer, and anyone can read it.

## More drywall Sheets

- **[Drywall for contractors](https://studsheet.com/trades/drywall)**: run this takeoff at your own prices, send the estimate, and get it signed and the deposit paid.
- **[Patch a hole in drywall](https://studsheet.com/sheets/patch)** (1 patch + 7 small holes): Spackle, patches, compound and primer for nail holes, dents, doorknob holes and bigger cut-outs, and how to make them disappear under paint.
- **[All 45 Sheets](https://studsheet.com/sheets)**, across 16 trades.
- **[Code reference](https://studsheet.com/codes):** frost depths, guard heights, stairs, retaining walls.