Drywall Calculator

Estimate sheets, joint compound, tape and screws for any room.

Quick start
Input mode

One side of the room.

The wall next to it.

Floor to ceiling (8 ft in most homes; 9–10 ft in newer builds).

Include ceiling?
Subtract openings?

Longer sheets mean fewer butt joints on long walls.

Picks the right product for the location — it does not change the sheet count.

Drywall waste comes from cutting around openings and off-cuts too small to reuse. Use 10%, or 15% for rooms with many openings, angles or small cuts.

Result

A 12 × 14 ft room, 8 ft walls, ceiling included needs about 21 sheets of 4×8 drywall.

You need21× 4×8 sheets

  • 4×8 sheets
  • ½" standard
  • 10% waste

What you’ll need

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See the full breakdown
Gross area
584.00 sq ft
With 10% waste
642.40 sq ft
4×8 sheets
21
Joint compound
77.1 lb (2 boxes)
Joint tape
257.0 lf
Screws
672

How this is calculated

  • Wall area = 2 × (length + width) × height (+ length × width if the ceiling is included).
  • Openings NOT subtracted — off-cuts around doors and windows are usually the waste.
  • Waste: +10% for cuts and off-cuts (use 15% for cut-heavy rooms).
  • Consumables: joint compound 0.12 lb/sq ft, tape 0.40 lf/sq ft, ~32 screws per sheet.
  • Ceiling screws: the count assumes ~1 screw/sq ft (wall spacing). Ceilings are fastened tighter — about 40+ screws per 4×8 sheet at 12" on center — so treat the screw total as a minimum and grab an extra box for the lids.
  • Board type: ½" standard for typical walls and ceilings. Sheet count is the same for every board type — it only changes the product you buy.

How much drywall do I need?

To figure out how much drywall you need, find your wall and ceiling area, add ~10% for waste, then divide by the sheet size — 32 sq ft for a 4×8 sheet or 48 sq ft for a 4×12. You’ll also need about 0.12 lb of joint compound and 0.40 linear feet of tape per square foot, plus roughly one screw per square foot. For example, a 12 ft × 14 ft room with 8 ft walls and a ceiling needs 21 sheets, about 77 lb of compound, 257 ft of tape and 672 screws. Enter your room above for a full materials list you can save or share.

How to use this calculator

  1. Choose an input mode. Enter room dimensions or a total wall/ceiling area.
  2. Add the ceiling. Include the ceiling if you’re boarding it, and pick your sheet size.
  3. Set waste. Keep 10% waste, or bump to 15% for cut-heavy rooms with many openings.
  4. Read your estimate. See sheets, joint compound, tape and screws, then save or share the list.

Tips & real-world notes

  • Don’t subtract small openings by default — the off-cuts around them are usually the waste.
  • Use 4×12 sheets on long walls to cut down on hard-to-finish butt joints where framing allows.
  • Ceilings use more screws and often 5/8" board for fire and sag rating — heavier to handle.
  • Corner bead, outside corners and control joints are separate line items, not in these totals.

Frequently asked questions

How much drywall do I need?
Find your wall and ceiling area, add ~10% for waste, and divide by the sheet size (32 sq ft for 4×8). A 12 × 14 room with 8 ft walls and a ceiling needs 21 sheets of 4×8 drywall.
How many sheets of drywall for a 12x14 room?
With 8 ft walls plus the ceiling and 10% waste, about 642 sq ft ÷ 32 = 21 sheets of 4×8, or roughly 14 sheets of 4×12.
How much joint compound and tape do I need?
Plan about 0.12 lb of ready-mix compound and 0.40 linear feet of tape per square foot of drywall — roughly one 4.5-gallon box of compound per 475 sq ft.
How many screws per sheet of drywall?
About 32 screws for a 4×8 sheet on walls at 16" on center, scaling to roughly one screw per square foot (about 48 for a 4×12). Ceilings use more.
Should I subtract doors and windows?
Usually no. Off-cuts around openings are typically too small to reuse, so leaving them in acts as your waste allowance. You can enable deductions for large openings.
What type of drywall should I use — ½", ⅝", green board or cement board?
½" standard is the default for most walls and ceilings. ⅝" Type X is fire-rated for garages, attached-garage ceilings and shared party walls, and resists sag on ceilings. Moisture/mold-resistant "green board" suits bathroom and laundry walls outside the shower. Cement board is the tile backer for showers, tub surrounds and other wet areas. The board type changes the product you buy, not the sheet count.
What drywall goes in a bathroom or behind shower tile?
Use moisture/mold-resistant "green board" on bathroom walls and ceilings that get humidity but stay dry, and cement board (or another approved tile backer) anywhere that gets wet — inside the shower, tub surround and splash zones. Standard drywall should not go behind tile in wet areas.
How much does it cost to drywall a room?
For a 12 × 14 room with 8 ft walls and a ceiling, the calculator lists 21 sheets of 4×8, about 77 lb of joint compound (2 boxes), 257 ft of tape and 672 screws. As a DIY materials-only estimate that is roughly $250–$450 depending on board type and local prices (⅝" and specialty boards cost more). Hiring a pro to hang, tape and finish typically runs about $1.50–$3.50 per square foot installed — for this room’s ~642 sq ft that’s roughly $1,000–$2,200. Turn on the cost option and enter your price per sheet for a live materials estimate.