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Drywall Calculator

Calculate how many sheets of drywall you need, plus joint compound, tape, screws, and corner bead

Room Dimensions

Openings to Subtract

Standard sizes are pre-filled. Adjust based on your actual measurements.

Drywall Options

Where walls meet walls
Requires corner bead

Drywall Type Guide

Regular Drywall

Also called: Whiteboard, Standard Drywall

The most common and affordable option for interior walls and ceilings. Available in 1/4", 3/8", 1/2", and 5/8" thicknesses. Best for dry, climate-controlled spaces.

  • Living rooms and bedrooms
  • Hallways and closets
  • Most interior applications

Moisture-Resistant (Green Board)

Also called: MR Board, Greenboard

Features a water-resistant core and facing. Not waterproof, but handles humidity better than standard drywall. Do not use in direct water contact areas.

  • Bathrooms (not in shower)
  • Laundry rooms
  • Basements

Fire-Rated (Type X)

Also called: Type X, Fire-Resistant

Contains special additives that slow fire spread. Required by code in garages, furnace rooms, and between living spaces. Typically 5/8" thick with 1-hour fire rating.

  • Attached garages
  • Furnace/utility rooms
  • Multi-family separations

Cement Board

Also called: Backer Board, Tile Board

Made from cement and reinforcing fibers. Completely waterproof and perfect as a tile substrate. Heavier and harder to cut than regular drywall.

  • Shower and tub surrounds
  • Kitchen backsplashes
  • Outdoor applications

Drywall Installation Tips

1. Hang Ceilings First

Always install ceiling drywall before walls. Wall sheets will help support ceiling edges and create cleaner corners.

2. Horizontal on Walls

Hang sheets horizontally on walls. This reduces seams, puts tapered edges at accessible heights, and creates stronger walls.

3. Stagger Your Seams

Never align seams vertically between rows. Stagger joints by at least 4 feet to prevent cracking and create stronger walls.

4. Don't Overtighten Screws

Drive screws just below the paper surface without breaking through. Broken paper means the screw won't hold properly.

5. Back-Cut Around Outlets

Cut outlet and switch openings from the back side. Score deeply, then break through from the front for clean edges.

6. Three Coats of Mud

Apply tape with first coat, feather with second, and finish with third. Sand lightly between coats after drying.

Tools You'll Need

Cutting Tools

  • Utility knife with extra blades
  • T-square (4 ft aluminum)
  • Drywall saw (jab saw)
  • Spiral saw or rotary tool (for outlets)
  • Rasp or surform for edges

Hanging Tools

  • Cordless drill/driver
  • Drywall screw setter bit
  • Drywall lift (for ceilings)
  • Deadman brace (DIY ceiling help)
  • Stud finder

Finishing Tools

  • Mud pan (12-14 inch)
  • Taping knives (6", 10", 12")
  • Corner trowel
  • Sanding pole with sanding screens
  • Shop light for inspecting

Safety Gear

  • N95 dust mask
  • Safety glasses
  • Work gloves
  • Drop cloths
  • Knee pads

Recommended Products

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Frequently Asked Questions

For a standard 12x12 room with 8-foot ceilings, you'll need approximately 12-14 sheets of 4x8 drywall for the walls only, or 16-18 sheets if you're also covering the ceiling. This includes a 10% waste factor for cuts and mistakes. The exact number depends on window and door openings and your cutting efficiency.

Plan for approximately 0.053 gallons (about 1/3 pound) of joint compound per square foot of drywall, or roughly 1.7 gallons per 4x8 sheet. A 5-gallon bucket typically covers 8-10 sheets for a three-coat finish. For your first project, buy extra - it's better to have too much than run out mid-project.

Use 1/2-inch drywall for most walls and ceilings with 16-inch on-center framing. Use 5/8-inch drywall for ceilings with 24-inch on-center framing, for better soundproofing, or where fire-rating is required (Type X). Use 1/4-inch only for curved surfaces or layering over existing walls.

Plan for approximately 32-36 screws per 4x8 sheet of drywall, or about 1 screw per square foot. For walls, screws should be spaced 16 inches apart on the edges and in the field. A 1-pound box contains roughly 200 screws, so a 5-lb box covers about 30 sheets.

Hang drywall horizontally on walls for stronger joints and fewer seams to tape. The horizontal orientation puts the tapered edges at more accessible heights and creates a stronger wall because the sheets bridge more studs. On ceilings, run the sheets perpendicular to the joists for maximum strength.

Joint compound (mud) is designed for taping seams and requires multiple coats and sanding. It comes in larger quantities and dries harder. Spackle is for small repairs and nail holes - it dries faster and doesn't require as much sanding, but isn't suitable for taping seams. Always use joint compound for new drywall installation.