Drywall Calculator

Drywall Calculator for Sheets, Mud, Screws & Cost

Enter your wall, room, or ceiling dimensions to estimate drywall sheets, screws, tape, joint compound, waste, and material cost in one place.

Works with 4x8, 4x10, and 4x12 sheets, plus door and window deductions.

Units:

Room Dimensions

Deductions

Enter dimensions above to see your drywall estimate.

How It Works

1

Select Room Type

Choose from single wall, rectangular room, L-shaped room, or ceiling.

2

Enter Dimensions

Input measurements, door/window counts, and choose sheet size and thickness.

3

Get Full Estimate

See sheets, screws, tape, compound, and total cost instantly.

See the Math: Real Drywall Examples

Every number below comes from the same formulas the calculator runs -- measure, deduct openings, add waste, divide by sheet size.

12'×12' Bedroom, 8-ft Ceiling

Rectangular room · 1 door, 2 windows · 4'x8' sheets, 1/2" · 10% waste

  • Gross wall area: 2 × (12 + 12) × 8 = 384 sq ft
  • Deductions: 21 + 2 × 12 = -45 sq ft
  • Area incl. 10% waste: 339 × 1.10 = 373 sq ft
  • Sheets: 373 ÷ 32, rounded up = 12 sheets ($168 at $14/sheet)
  • Plus 339 screws, 85 ft of tape, 18 gal of compound

12'×14' Garage Ceiling

Ceiling · no openings · 4'x8' sheets, 5/8" for sag resistance · 10% waste

  • Ceiling area: 12 × 14 = 168 sq ft
  • Area incl. 10% waste: 185 sq ft
  • Sheets: 185 ÷ 32, rounded up = 6 sheets ($108 at $18/sheet)
  • Plus 168 screws, 42 ft of tape, 8.9 gal of compound

14'×9' Accent Wall

Single wall · no deductions · 4'x10' sheets, 1/2" · 10% waste

  • Wall area: 14 × 9 = 126 sq ft
  • Area incl. 10% waste: 139 sq ft
  • Sheets: 139 ÷ 40, rounded up = 4 sheets ($56 at $14/sheet)
  • Plus 126 screws, 32 ft of tape, 6.7 gal of compound

L-shaped rooms work the same way -- run your own dimensions in the calculator.

Guides & Deep Dives

Go deeper on sheet selection, the full formula, installation, and cost planning.

Drywall Sheet Calculator

Compare 4'x8', 4'x10', and 4'x12' sheets to pick the size that cuts seams and waste

How Much Drywall Do I Need?

Step-by-step formula walkthrough for any room, from a single wall to a whole house

How to Hang Drywall

Layout planning, clean cuts, screw spacing, and seam placement for DIY installs

Drywall Sheet Sizes Guide

Weight, price, and ideal use for every standard sheet size

What Drywall Really Costs

Material and labor cost pitfalls, and why the cheapest bid gets expensive

Drywall vs Plaster

Cost, durability, and repair difficulty compared for older homes

Why Use Our Drywall Calculator?

Accurate Estimates

Industry-standard formulas with adjustable waste factor for precise material quantities.

Door & Window Deductions

Automatically subtract doors, windows, and custom openings from your total area.

Complete Material List

Get sheets, screws, joint tape, and joint compound quantities in one place.

Cost Breakdown

See total drywall cost based on your selected sheet size and thickness.

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Frequently Asked Questions

How do I calculate how much drywall I need?
Measure the total wall or ceiling area in square feet (height x width for each surface), subtract door and window openings, then divide by the sheet size you plan to use (32 sq ft for 4'x8' sheets). Add 10% for waste and cuts.
What size drywall sheets should I use?
4'x8' sheets are the most common and easiest to handle. 4'x12' sheets are ideal for rooms with 9-foot or higher ceilings because they reduce the number of seams. 4'x10' sheets split the difference for standard 8-foot walls hung horizontally.
How thick should drywall be?
1/2" is the standard thickness for most walls. 5/8" is required for ceilings (to prevent sagging), garage walls adjacent to living spaces (fire code), and fire-rated assemblies. 1/4" and 3/8" are used for curved walls and overlay repairs.
How many screws do I need for drywall?
A good rule of thumb is about 1 screw per square foot of drywall, or roughly 28-32 screws per 4'x8' sheet. Screws should be placed every 12 inches along edges and every 16 inches in the field (center of the sheet).
How much joint compound do I need?
Plan for approximately 0.053 gallons (about 3.5 pounds) of joint compound per square foot of drywall. A 4.5-gallon bucket covers roughly 85 square feet of drywall for three coats of taping, bedding, and finishing.
What is the difference between drywall and sheetrock?
Sheetrock is a brand name for drywall made by USG Corporation. Drywall is the generic term for gypsum board panels. They are functionally identical -- "sheetrock" is simply the most well-known brand, similar to how "Kleenex" refers to tissue.
Should I hang drywall horizontally or vertically?
Horizontally is preferred for walls because it reduces the total linear feet of seams, creates stronger joints across studs, and is easier to finish. Vertical hanging is acceptable for walls shorter than 4 feet or in commercial applications with metal framing.
How much does drywall cost per sheet?
Standard 1/2" thick 4'x8' drywall costs about $12-$16 per sheet. 5/8" fire-rated sheets cost $16-$22. Moisture-resistant (green board) costs $14-$20. Prices vary by region, quantity, and supplier.
How much waste factor should I add?
Add 10% for standard rectangular rooms. Use 15% for rooms with many openings (doors, windows) or complex layouts. For L-shaped rooms or rooms with angles, 15-20% is recommended because of increased cutting waste.
Can I install drywall on a ceiling myself?
Yes, but it is significantly harder than walls. Use 5/8" drywall for ceilings to prevent sagging. A drywall lift (rentable at most hardware stores) is almost essential for ceiling work. Screws should be spaced every 12 inches on ceiling joists.

Trusted Drywall & Construction Resources

Gypsum Association

Official drywall specifications and installation standards

OSHA Drywall Safety

Federal workplace safety standards for drywall installation

Building Science Corporation

Research on airtight drywall approaches and energy efficiency

National Association of Home Builders

Industry standards and contractor resources for drywall projects

Explore related pages

Drywall cost pages added this cycle

The drywall cluster now separates repair, installation, finishing, and sheet-count intent.

Drywall Finishing Cost Calculator Tool page Drywall Installation Cost Calculator Tool page Drywall Repair Cost Calculator Tool page

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